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Row house 2002 · somewhere in the Randstad (NL) · design v8, 4 November 2026

District heating out, Haier AW062 monobloc in: who will review my design and 13 open questions?

I'm replacing disconnected district heating (Eneco) with a Haier AW062MUGHA monobloc (6 kW, R290) with the ATW-A03N control box and the HW-WA101DBT wired controller. Hydraulics: Haier → 3-way valve → (a) a Haier WT60V 60 L buffer, connected in parallel (4 ports), with a second pump to 6 Jaga convectors, and (b) a Haier WT200V 200 L DHW tank (2.0 m² coil, 2.5 kW element). Room control stays Honeywell Evohome; the BDR91 goes volt-free to CN13 ZONE1 ON/OFF. An installation company does all the work (ISDE subsidy).

The Haier documentation leaves a few things open. Does anyone have experience with the ATW-A03N / HW-WA101DBT, or with a similar setup? The house has no heating and no hot water right now, so every tip helps.

How to reply: in the forum thread, with the question number (e.g. “V7: on mine K is 230 V during hot water, valve X …”). The numbers are the same as on the Dutch page (V = vraag, question). Click a number such as V7 to copy a direct link to that question, or use the reply template.
18 GJ/yearreal district-heating use (≈ 5,000 kWh), steady for 4 years
≈ 2–3 kWpeak demand on the coldest day (from the real use)
6 kW R290Haier AW062MUGHA, already bought (Dec 2025)
60 L + 200 Lparallel WT60V buffer + WT200V DHW tank
6 Jaga'sconvectors, designed for ≈ 70 °C
3 × 25 Agrid connection; panel full → separate heat-pump sub-panel

The 13 questions

Under each question: where the background is on this page, and which pages of the Haier documents I have already read. IM = R290 Monobloc installation manual (22-01-2025) · DB = Engineering DataBook (SYJS-07-2024 REV.B) · ATW = ATW-A03N installation manual (2025-04-03). Page numbers = printed numbers.

A. ATW-A03N control box and HW-WA101DBT controller

V1 Which tank-sensor input with a single tank sensor: T_tank up (CN50) or T_tank down (CN48)?

The ATW-A03N has two tank inputs: CN50 "T_tank up" and CN48 "T_tank down". The Haier WT200V has only one sensor pocket, low in the element flange. Which input does that one sensor go on? Does the controller show error E10 if the other input stays empty, and do you then have to switch something off in the menu?

Background: ATW-A03N connections · WT200V · schematic part (5). Documents: ATW p. 9 (CN48/CN50) · IM p. 39 (E10) · WT200V p. 6 and 8.

V2 Which setting makes the BDR91 on CN13 ZONE1 ON/OFF work?

I want Evohome (BDR91, volt-free contact) to switch CN13 ZONE1 ON/OFF. The installer menu has "Control Mode of Zone1": Main controller / Third party controller / Thermostat, and "Third Party Controller Type": Type 1 / Type 2. I think: Third party controller, Type 2, with the HEAT/COOL contact left open (= heating). Is that right? Does the compressor stop immediately when ZONE1 opens, or does it finish charging the buffer first?

Background: Evohome · settings. Documents: IM p. 57–58 · DB p. 69 (third-party control, Type 1/2) · ATW p. 11–12.

V3 Short cycling caused by Evohome: any experience with BDR91 → ZONE1 ON/OFF and a parallel buffer?

Even at its lowest setting, Evohome switches the BDR91 3 times per hour (TPI, min. ON 5 min). Has anyone measured whether a Haier then short-cycles, even with a 60 L parallel buffer? My fallback: ZONE1 permanently on in winter, and the BDR91 only switches pump 2 (PUMP1 output → BDR91 COM/NO → pump 2). Is the BDR91 contact suitable for a ≈ 45 W pump at 230 V?

Background: short-cycling check and fallback · Evohome. Documents: IM p. 57 ("ΔT for Heating On").

V4 How should the Haier's internal pump be set with a parallel buffer, and does pump 2 keep running during hot-water charging?

"Indoor unit installation" has "Pump Flow Rate Control Mode" (ΔT between out and in water / Constant speed duty out; default Constant speed) and "IDU Pump Duty Out" (0–100 %, default 0 %). What does 0 % mean: maximum, automatic or off? I want a fixed ≈ 1.0 m³/h (primary ≥ secondary). And: does the PUMP1 output (pump 2, radiators) stay on while the tank is being heated?

Background: two-loop principle · settings. Documents: IM p. 59 · ATW p. 13 (PUMP1 max. 180 W).

V5 Does "Schedule" also work for hot water (time window 11:00–15:00)?

I want the tank to heat only between 11:00 and 15:00 (solar panels), but still reheat in the evening if it really runs empty. Can "Schedule" (time block with mode and temperature) do that, e.g. DHW 48 °C from 11 to 15 h and ≈ 41 °C the rest of the day? Or is the SG-ready input (CN47) with a timer switch better?

Background: solar vs. heat pump · settings. Documents: IM p. 49–50 (Schedule), p. 56 (SG Ready), p. 57 (Tank Re-heat Temp.) · ATW p. 11–12.

V6 Energy meter on CN52: which kWh meter with pulse output?

The Haier can show its own consumption with an external pulse meter on CN52 EM ("Pulse Selection for power consumption": 1/10, 1/1, 10/, 100/kWh). Does the HomeWizard 1-phase kWh meter have a pulse output (S0), or should I take an Eastron SDM120? Has anyone connected this?

Background: sub-panel, E6 · short-cycling check. Documents: IM p. 54 · ATW p. 14 (CN52 EM/HM).

B. Hydraulics

V7 3-way valve direction: does the Haier put 230 V on K for hot water?

The ATW-A03N has terminals L, N, K ("live, neutral, control") for the 3-way valve. Is K = 230 V during hot water (and K = 0 during space heating)? Haier's own example drawing calls the tank port "A" and the buffer port "B", the opposite of many valves. Which valve do you use with a Haier (e.g. Rekx OKO1, VC6013 type), and did you have to change anything on it?

Background: principle · schematic · valves in the parts list. Documents: ATW p. 13 (terminals 1–3) · IM p. 24 (example diagram: A → tank, B → buffer).

V8 Floor-heating group without a (known) oxygen barrier: is a plate heat exchanger needed?

The house has an old WTH floor-heating unit (own Grundfos UPS 25-40, thermostatic mixing valve) for the bathroom floor, unused for 4 years. If the blue floor pipe has no oxygen barrier (no print "EVOH / zuurstofdicht / DIN 4726"): is a small plate heat exchanger really needed, or would something else do? And can such a group with its own pump simply go on the secondary side of the buffer (next to the radiators)?

Background: floor heating, phase 1 and 2 · schematic box "WTH floor-heating group".

V9 Do the Haier sensors (0150408957) fit the WT200V sensor pocket and the WT60V measuring port?

Has anyone fitted the supplied Haier temperature sensors (part no. 0150408957) into a Haier WT200V (pocket in the flange) and a Haier WT60V (front measuring port)? What is the sensor diameter, and did you need an adapter or thermal paste?

Background: tank & buffer · schematic parts (4) and (5). Documents: DB p. 129 · WT200V p. 8 · WT60V p. 2.

C. Tank element and electrical

V10 Which thermostat of the WT200V element is adjustable (RT or MT), and how high?

According to its wiring diagram, the 2.5 kW element of the Haier WT200V has two thermostats in series: RT ("normal temperature thermostat") and MT (in German "manueller Thermostat"). Which one is adjustable, and up to what temperature? I want the anti-legionella cycle at 60 °C (default is 75 °C), so the adjustable thermostat must be at least 65 °C. Is MT a manual-reset safety cut-out?

Background: WT200V · Sterilization. Documents: WT200V p. 5 (MT/RT/EH/HL) · IM p. 54 (Sterilization 50–75 °C, default Mon 23:00, 75 °C).

V11 Cable type: XMvK/YMvK or H07RN-F to the outdoor unit?

Haier specifies H07RN-F "or the electrically equivalent type" for the power and interconnection cables. Can the fixed run to the front facade be XMvK/YMvK 3 × 4 mm², with only the last flexible part in H07RN-F? What do installers do in practice (NEN 1010)?

Background: sub-panel, E2/E5. Documents: IM p. 7 and from p. 29 · DB p. 19 (min. 4 mm², MCA 13.5 A, MFA 16 A).

D. Other

V12 Jaga convectors at 45–55 °C: enough output in the coldest rooms?

My Jaga's were sized for district heating (≈ 70 °C). The smallest: 10.5 × 72 cm (coldest room, top floor) and 20 × 72 cm. Who has experience with Jaga's at 45–55 °C supply? Is a DBE booster or a bigger Jaga usually needed?

Background: rooms and radiators · heat demand.

V13 Price check: 20 A RCBO type A, ≥ 30 mm insulation, raised stand

Is ≈ €30–55 right for an RCBO 20 A, 30 mA, type A, 1P+N (Hager ADA920G / ABB DS201 B20 A30), ≈ €60–110 for 10 m of 30 mm insulation, and ≈ €20–50 for a raised stand for the outdoor unit? Where do you buy these cheapest?

Background: parts & cost. Documents: IM p. 26 (insulation ≥ 30 mm), p. 19–20 (placement).

Also welcome: comments on the parts choice (tank, buffer, 3-way valve, pump, anti-freeze valves), or on anything I've completely overlooked.

1. The house and the old situation

TypeRow house, built 2002, somewhere in the Randstad
Living space145 m² over 3 floors; footprint 12.4 × 5.4 m (≈ 67 m² per floor)
Heated rooms6: living room, 4 bedrooms/offices, bathroom
EmittersJaga convectors, a small bathroom radiator and an existing WTH floor-heating group (unused for 4 years)
ControlsHoneywell Evohome: ATC928 controller, 4 × HR92, T87RF (bathroom), BDR91. Parents' bedroom: manual valve.
Solar panels16 × Trina 455 Wp, half NE, half SW; Sungrow SH3.6RS inverter (own group). Real yield ≈ 5,520 kWh/year.
Old systemEneco district heating, direct system: the network water went straight through the radiators (no own pump or expansion vessel). Tap water via a plate heat exchanger. Delivery set removed in March 2026; now no heating and no hot water.

Rooms without heating at −6 °C outside

FloorRoomm²Temp.Jaga (h × w)Control
grLiving room4313 °C19×140 + 19×135HR92
1Parents2112 °C19×92manual, always open
1Kid1912 °C9.5×201HR92
2Office2311 °C20×72 ⚠HR92
2Meditation room1310 °C10.5×72 ⚠HR92
2Bathroom414 °Csmall, size unknownT87RF

The meditation room is the coldest: it has one more outside wall than the others. The other rooms border heated neighbours.

Aerial photo of the front facade with the meditation room (2nd floor) and bedroom 2 marked
Front facade from above. Yellow = meditation room (2nd floor, under the roof, coldest room), green = bedroom 2. Solar panels on the roof.

Heat demand from the real consumption

  • 18 GJ/year of district heat (steady for 4 years) = ≈ 5,000 kWh, for space heating and tap water together.
  • Tap water: 11 showers/week (2 adults, 2 teenagers), 8 L/min → ≈ 970 kWh; kitchen ≈ 225 kWh; losses of the old set ≈ 330 kWh → ≈ 1,530 kWh.
  • Space heating ≈ 3,470 kWh/year ÷ 1,400–1,800 full-load hours → ≈ 1.9–2.5 kW, with margin 2–3 kW on the coldest day.
  • A rough per-room estimate (everything 20 °C all day) gives 4.1–5.1 kW at −6 °C; real use is more economical (zoning, cool bedrooms).
  • The installer will do a heat-loss calculation (ISSO 51).
Haier AW062 (max.)Water 45 °C50 °C55 °C
−7 °C outside5.2 kW · COP 3.04.8 · 2.74.3 · 2.4
−10 °C outside5.0 kW · COP 2.84.5 · 2.53.9 · 2.2

Source: Engineering DataBook. Minimum output ≈ 1.2–1.6 kW, while the house needs only 0.3–1 kW in spring and autumn. That is why there is a buffer.

The pipes in the meter cupboard

The rail has four capped connections, stamped KW – WW – A – R: 1 cold water in, 2 hot water to the taps, 3 radiator supply, 4 radiator return. The old Honeywell VC8015 zone valve on pipe 4 is replaced by a straight coupling. The fitting under pipe 1 is the old, weeping inlet safety group (inlaatcombinatie); it is replaced, and its drain to the sewer is reused.

2. Hydraulic design (Plan B)

Principle schematic v7: Haier AW062, 3-way valve, WT60V parallel buffer, WT200V tank, 18 L expansion vessel, Evohome, sub-panel
Principle schematic v7 (click to enlarge; click again for 100 %). It shows how everything is connected, not where it stands. Port heights in mm above the floor, from the Haier drawings (±10 %).

Impression of the end result

AI impression, not a photo. This is roughly how it should look; nothing has been installed yet. The schematic above is leading.
AI impression: Haier outdoor unit at the front facade, tank and buffer in the storage room, meter cupboard
Without numbers. Left the outdoor unit on a raised stand, middle the storage room with buffer and tank, right the meter cupboard.
AI impression with part numbers
With numbers (roughly following the schematic). Some labels don't match the design: "8" appears twice and "15" three times; "16" and "17" (pressure gauge and filling set) sit on top of the buffer; "4" (the buffer sensor) points at a pressure gauge; "E6" points at an existing box instead of the kWh meter in the new sub-panel. The design itself is fine; only the picture is off.

Principle: two loops with a parallel buffer

  • Loop 1, Haier ↔ buffer / tank coil. The Haier's internal pump (PUMP_0, "pump 1") runs ≈ 1.0 m³/h. Nothing in loop 1 can close. The 3-way valve sits right after the Haier: heating port → buffer, DHW port → tank coil. Ports are named by function here, because the letters differ per manufacturer (V7).
  • Loop 2, buffer ↔ radiators. Pump 2 (Wilo Para 25/6, Δp-v, 0.6–0.8 m³/h) draws from the WT60V's upper right port and feeds pipe 3. The return (pipe 4) goes only into the lower right port, never directly into the Haier return.
  • WT60V 60 L in parallel (4 × 1¼"): separates the loops, covers defrost, and gives ≈ 1 start per hour at low load (6 K switching band ≈ 0.42 kWh per cycle).
  • WT200V 200 L: 2.0 m² coil in counter-flow (in at 930 mm, out at 290 mm). Tank at 48 °C, preferably heated between 11 and 15 h. Anti-legionella: Sunday 13:00 to 60 °C, the last degrees by the 2.5 kW element via the built-in relay of the ATW-A03N.
  • Common return (J1): 18 L expansion vessel (pre-charge 1.0 bar, capped valve) → Dirtmag → Y-filter → Haier.
  • A specialist who visited on 3 November drew the same principle (photos).
  OUTSIDE ┊ INSIDE
 ┌──────┐┊           ┌────────────┐ heating      ┌──────────────┐
 │HAIER │═(1)═(2)═(3)►│ 3-WAY VALVE│═════════════►│UL  WT60V   UR│═(14)═► PUMP 2 ═(15)═► pipe 3 ═► JAGA's
 │AW062 │┊   air vent │ AB→heat/DHW│              │   60 L  (4)  │                              (HR92)
 │pump 1│┊           └─────┬──────┘              │LL          LR│◄══════ pipe 4 ◄══════════════╝
 └──▲───┘┊                 │ DHW (K)             └──┬───────────┘
   (11)  ┊      ┌──── ④ coil in (930) ───────┐      ┆
    ┆    ┊ CW ··(12)··► ⑥ (245)   ① (1055) ··► (13) ··► pipe 2 (hot tap water)
    ┆    ┊      │ WT200V 200 L · T_tank (5)  │      ┆
    ┆    ┊      └──── ⑤ coil out (290) ──────┘      ┆
    └-(10)-(8)-(7)-(9)- - - - J1 - - - - - - - - - -┘
        Y-filter Dirtmag  expansion vessel 18 L

UL/UR = upper left/right (≈ 500 mm), LL/LR = lower left/right (264 mm), all 1¼" female. Numbers in brackets = part numbers.

Numbered parts 1–23 (as in the schematic)
#PartLocation
1 / 11Anti-freeze valve Caleffi iStop 1" (supply / return)Outside, close to the Haier, low
2 / 10Shut-off valve 1" full boreSupply / return, inside
3 / 3bAutomatic air vent ½"Highest point of supply / top of WT60V (¾"→½")
4Sensor T_buffer → CN3WT60V front measuring port
5Sensor T_tank → CN48 or CN50 (V1)Pocket in the WT200V flange
6, 16, 17Fill/drain valve, pressure gauge 0–4 bar, EN 1717 filling setWT60V refill port; hose removed after filling
7 / 8Magnetic dirt separator / Y-filter (with the Haier)Common return
9Expansion vessel 18 L, pre-charge 1.0 bar, capped valveCommon return, between J1 and 7
12New inlet safety group 8 bar (KIWA)Pipe 1 → tank ⑥
13Thermostatic mixing valve ¾", 50–55 °CTank ① → pipe 2; cold taken after 12
14 / 15Pump isolation valvesAround pump 2
18 / 19 / 20T&P valve (supplied) / drain valve ¾" / funnel with siphonTank ② / ⑦ / next to the tank or existing drain
21Optional drinking-water expansion vessel 8–12 LBetween 12 and ⑥
22Element 2.5 kW (in the tank)Via the tank-heater relay in the ATW-A03N
23Existing WTH floor-heating groupTee on pipes 3 + 4; closed in winter 1
Port-by-port connection table
FromViaToNote
Haier outlet R1" male1 → 2 → 33-way valve AB 1"28 mm
3-way valve heating port–WT60V upper left (≈ 500 mm)reducer 1¼" M × 1" F
3-way valve DHW port–WT200V ④ coil in G1 (930 mm)union
WT200V ⑤ coil out (290 mm) + WT60V lower left (264 mm)–J1tee 28 mm
J19 → 7 → 8 → 10 → 11Haier inlet R1"Y-filter in flow direction
WT60V upper right14 → pump 2 → 15pipe 3arrow away from the buffer
pipe 4–WT60V lower rightonly here
pipe 1 (cold)12 (→ 21)WT200V ⑥ G1 (245 mm)adapter 1" × 22 mm
WT200V ① G1 (1,055 mm)13pipe 2–
WT200V ② G¾ (1,055 mm)18funnel 20discharge always open, pointing down
Water volume and expansion vessel

Radiators ≈ 8–14 L, pipes ≈ 15–20 L, buffer 60 L, coil ≈ 10–12 L, Haier + outdoor pipes ≈ 5–10 L → ≈ 100–115 L (phase 2 with floor loops ≈ 130 L). Expansion 10 → 75 °C ≈ 3.0 L + 3.0 L reserve. Static height 6 m → pre-charge 1.0 bar; pe 2.5 bar (safety valve 3 bar) → usable fraction 0.43 → ≈ 14 L total − 4.5 L built-in ≈ 9.5 L → chosen 18 L. Haier: the built-in 4.5 L vessel covers max. 78 L (IM p. 26). Fill pressure 1.5 bar cold, 1.8–2.2 bar warm.

3. Controls: Evohome, ATW-A03N and settings

Role of Evohome

ATC928 + app, HR92's, T87RFUnchanged: temperature and schedule per room
BDR91Becomes a boiler relay / heat demand (not a zone valve). COM/NO volt-free to CN13 ZONE1 ON/OFF. The old 24 V wires of the VC8015 come off the contact first. Cycle rate 3/h (lowest), min. ON 5 min.
VC8015 zone valveRemoved (straight coupling), transformer removed
Parents' bedroomManual valve stays open = minimum flow for loop 2
Division of tasksEvohome decides which rooms get heat and whether heat is needed. The Haier decides how warm (heating curve), keeps buffer and tank at temperature and switches pump 2 (CN37 PUMP1).

Connections in the ATW-A03N

DeviceTerminalNote
3-way valve"3-way Valve" L, N, K (power terminals 1–3)Expected: K live = DHW, K dead = heating. Not in the documents → V7
Pump 2CN37 "PUMP1" (230 V)max. 180 W / 0.6 A; Wilo Para ≤ 43 W
T_bufferCN3Haier sensor in WT60V
T_tankCN50 "T_tank up" or CN48 "T_tank down"V1
Evohome BDR91CN13 "ZONE1 ON/OFF"Third party controller, Type 2 (V2)
Tank element 2.5 kWTerminals 2/4 of the built-in tank-heater relay (driven via CN43)≤ 3 kW / < 20 A allowed; 3 × 2.5 mm²; plug removed, wired directly. No external contactor any more.
OLP inputsCN51 (tank heater), CN55 (backup heater)Must be closed → bridge them
DIP BM1Main boardSet to 6 kW
Outdoor unitP/Q2 × 0.75 mm² shielded, shield earthed at one point
OptionalCN47 SG-ready · CN52 EM (pulse meter)V5, V6
ATW-A03N supplyL, N, PERCBO 20 A 30 mA type A, 3 × 4 mm² (≤ 25 m), phase L-b; the box has its own MCB

Mind the naming: for Haier, "PUMP_0" is the pump inside the outdoor unit (pump 1 here) and "PUMP1" is the output for the external pump (pump 2 here).

Planned HW-WA101DBT settings (Haier menu names)

SettingValueHaier default / note
"Zones Water Temp. Control Mode"Set curve: −7 → 50 °C · 0 → 44 · +7 → 38 · +15 → 32default Direct
"Ambient Temp. of Heating Off"16 °Cdefault 27 °C
"ΔT for Heating On" (buffer switching band)6 Krange 0–15 K; 8 K if short-cycling
Tank setpoint48 °C≈ 245 L of 40 °C shower water
"Max Temp DHW with HP only"50 °Cdefault 45 °C, max. 55 °C
"Tank Re-heat Temp."−6 K (restart ≈ 42 °C)default −3 K
DHW time window11:00–15:00 via "Schedule", ≈ 41 °C outside itV5
"Sterilization"On, Sunday 13:00, 60 °C, ≥ 30 mindefault Mon 23:00, 75 °C (V10)
Adjustable element thermostat≥ 65 °CRT or MT? (V10)
"Pump Flow Rate Control Mode" / "IDU Pump Duty Out"Constant speed, duty so that ≈ 1.0 m³/hdefault 0 %, meaning unknown (V4)
"Selection of IDU Electric Heating Type"Nonedefault Heater 1 & 2
"Equipment installation"Zone 1 On · DHW On · Buffer Tank On · Allow tank heater On (2.5 kW)default DHW/Buffer/tank heater Off
"Control Mode of Zone1" / "Third Party Controller Type"Third party controller / Type 2V2
"Quiet"On, 22:00–07:00outdoor unit at the front facade
Pump 2Δp-variable, ≈ 0.6–0.8 m³/hslightly below the Haier flow
Pressure1.5 bar cold, 1.8–2.2 warmHaier min. flow 0.41 m³/h (E08)

Short-cycling check in the first 14 days

Because Evohome was made for gas boilers and switches up to 3 times per hour, I will log the compressor starts with kWh meter E6 for the first 14 days (power > 300 W = one start). Judging at +5 to +12 °C outside:

ResultMeaningAction
≤ 2 starts/hour and runs ≥ 15 minGoodNothing
3–4 starts/hour or runs 10–15 minBorderlineΔT for Heating On 6 → 8 K; check the Evohome settings
> 4 starts/hour or runs < 10 minShort cyclingAlso lower the heating curve 1–2 °C; no improvement after 3 days → fallback
Starts exactly when the BDR91 switchesEvohome drives the cyclingFallback

Fallback: ZONE1 permanently on during the heating season, so the Haier controls on T_buffer only. The BDR91 contact moves into the live of pump 2: CN37 PUMP1 L → BDR91 COM → NO → pump 2. Pump 2 then runs only when the Haier allows it and Evohome asks for heat (V3).

4. WT200V tank and WT60V buffer

Haier WT200V-SCA3E(EU)

Volume200 L (193 L usable)
Coil2.0 m², max. 10 bar / 80 °C
VesselEnamelled steel, magnesium anode at the top (≥ 40 cm free above)
Pressure8.5 bar nominal, max. 9.5 bar → 8 bar inlet safety group
Element2.5 kW, 230 V, thermostats RT + MT in series (V10)
Heat loss65 W (ErP C)
SizeØ 600 × 1,320 mm, full ≈ 260 kg
Ports (one side)① hot G1 1,055 · ② T&P G¾ 1,055 · ④ coil in G1 930 · ⑤ coil out G1 290 · ⑥ cold G1 245 · ⑦ drain G¾ 245 mm · one sensor pocket in the flange

Haier WT60V-NCA5(EU)

Volume60 L, 8 bar, 0–90 °C
SizeØ 482 × 738 mm, full ≈ 85 kg, floor-standing, secure with angle brackets
Insulation50 mm PU, ≈ 39 W at 65 °C (≈ 13–15 W at 35 °C)
Water ports4 × 1¼" F (DN32): UL/UR ≈ 500 mm, LL/LR 264 mm
OtherAir vent at the top ¾" · front measuring port (≈ 380 mm) · refill port · magnesium rod (supplied loose)

Placement: side by side on the floor in the storage room at the front (floor plan), as close to the meter cupboard as possible (≈ 1.2 m wall width, 0.65 m deep). Stacking the buffer on the tank was ruled out: ≈ 2.6 m high, and the anode can't be reached. A combined tower was ruled out too: no reliable seller.

Drinking-water side: new KIWA inlet safety group 8 bar; T&P valve on ②; thermostatic mixing valve 50–55 °C on ① (cold taken after the inlet safety group); weekly anti-legionella cycle ≥ 60 °C. Each heat-up drips ≈ 3 L from the overflow; a drinking-water expansion vessel (21) is optional.

5. Existing floor heating (WTH group)

In a cupboard ≈ 1.5 m from the meter-cupboard pipes is a red WTH floor-heating manifold with its own Grundfos UPS 25-40 180 (30/45/60 W, unplugged), a thermostatic mixing valve with sensor (setting 5), a second thermostatic head on the return, and supply/return thermometers. It is connected by a tee to pipes 3 and 4. It probably heats the bathroom floor (still to confirm with the former owner). It hasn't been used for 4 years.

PhaseWhat happens
Winter 2026–27The group's valves are closed (or two ball valves are fitted on the tee). Its old water stays out of the new system and the pump stays off.
Spring 2027Flush the loops separately; replace the pump (Wilo Para / UPM3, 180 mm). Oxygen barrier: with the print "EVOH / zuurstofdicht / DIN 4726" or Alu-PEX, connect directly; otherwise separate with a small plate heat exchanger (V8). Let the pump run only together with pump 2; mixing valve at ≈ 30–35 °C.

Effect on the design: ≈ 5–15 L extra water; the 18 L expansion vessel is still enough (≈ 10.5 L needed).

6. Electrical

Existing meter cupboard

  • Grid connection 3 × 25 A, smart meter with a P1 dongle (power per phase visible).
  • Main switch ABB 3-pole 40 A.
  • Group panel Holec/Hafonorm (2003). Row 1: RCD ABB F204 A 40 A/30 mA with a 2-pole cooker group + 3 groups B16. Row 2: RCD 40 A/30 mA with 3 groups B16 (smoke detectors). Only 1 free module per row → full.
  • PV: separate small box with a Noark RCBO B20 30 mA → Sungrow SH3.6RS. Stays as it is.

I'll find the phases with the P1 meter: kettle on → which phase jumps; cooker zones one by one → the two cooker phases; sunny moment → the phase with negative power = PV.

Meter-cupboard strip from schematic v7: existing panel, PV group and new heat-pump sub-panel
Strip from the schematic: existing + new sub-panel.

New heat-pump sub-panel "WP-kast" (E1), next to the PV box

Main switch ABB 40 A (outputs)
 └── feed 6 mm²: L-a, L-b, N, PE ──► E1 WP-kast (surface box, 12 modules)
       ├── E2 RCBO C16 30 mA type A (L-a) ── E6 kWh meter ── 3 × 4 mm² ── E5 isolator ── Haier AW062
       └── E4 RCBO 20 A 30 mA type A (L-b) ── 3 × 4 mm² (≤ 25 m) ── ATW-A03N
                                              ├─ 3-way valve, pump 2 (CN37), sensors
                                              └─ built-in relay (2/4) ── 3 × 2.5 mm² ── element 2.5 kW
CodePartWhy
E1Surface box 1 row, 12 modules, IP40Panel full; existing RCDs stay untouched
E2RCBO C16, 30 mA, type A, 1P+N, 6 kADB: max. fuse 16 A, MCA 13.5 A, cable ≥ 4 mm². Phase L-a = the phase without the cooker.
E4RCBO 20 A, 30 mA, type A, 1P+NATW p. 7: "with tank heater" 20 A, 4 mm². Phase L-b (a cooker phase); the element runs only for anti-legionella/backup.
E5Isolator ≥ 25 A, IP65, lockableAt the outdoor unit (NEN 1010)
E61-phase MID kWh meter on E2 (HomeWizard or Eastron SDM120)Real SCOP + short-cycling check; pulse for CN52? (V6)
–Cables: 3 × 4 mm² outdoor (XMvK/YMvK or H07RN-F, V11) · 3 × 4 mm² to the ATW · 3 × 2.5 mm² to the element · P/Q 2 × 0.75 mm² shielded · 2-core BDR91 → CN13

Worst-case load (cold winter evening, everything on): L1 ≈ 21 A, L2 ≈ 20 A (+ 11 A element only during the anti-legionella hour), L3 ≈ 17 A (heat pump at max. 3.1 kW ≈ 22 A). The installation company builds, connects and tests the sub-panel (ISDE).

7. Outdoor unit

Haier outdoor unit against the front facade, next to the storage-room door
Planned position of the Haier against the front facade, behind the fence and next to the storage-room door.
Ground-floor plan: hallway, toilet, storage room with tank and buffer, Haier outside
Ground-floor plan (front). The tank and buffer (two circles) go in the storage room, right behind the outdoor unit, so the pipes into the house stay short.

8. Parts and cost

The installation company installs everything (required for ISDE); I may buy the materials myself. ✅ = my pick. Prices incl. VAT, checked 2–4 November 2026.

Part✅ PickPriceAlternatives
DHW tank 200 LHaier WT200V-SCA3E (Hornbach.de)€795ThermoFlux SWPN 200 €734 · Intergas Xylinder WPSAE200 €1,319 (NL, fast)
Buffer 60 LHaier WT60V-NCA5 (mdpcloud, LT)€181Hornbach.de €295 · WT80V €318 · DRL 50 L wall-hung, 4 × 1" €411 (NL)
Expansion vessel 18 L, 1 barBonfix / Reflex (Vekto)€41 + €20 bracket/capped valveLevica €35 · Zilmet ≈ €38 · Flamco Flexcon €87
3-way valve 1" 230 V, L/N/KRekx OKO1€129generic €98 · VC6013 type €165 · Nefit-Bosch 28 mm €180 (V7)
Anti-freeze valve 1" × 2Caleffi iStop 108602 (Technim)2 × €75iStop LT €79 · Raminex €103
Dirt separatorCaleffi Dirtmag 22 mm + reducers€108IBO 1" €71 · Dirtmag 28 mm €135 · DiscalDirtmag 1" €139
Pump 2Wilo Para 25/6-43/SC 180 mm€150 + €30 isolation valvesGrundfos UPM3 Auto 25-70 €180
Mixing valve ¾" 35–60 °CESBE VTA322€86Watts Instamix ≈ €70–100
Inlet safety group 8 bar KIWAInovario set (Gamma) + funnel€63VSH / Bonfix ≈ €30–50
Air vents ½" × 2Flamco Flexvent 27740€30Caleffi Robocal · Spirotop
Sub-panel E1, E2, E4, E5, E6 + cablessee electrical≈ €315(V13)
Ball valves, fill valve, drain, gauge, brackets, EN 1717 filling set–€140
Reducers 1¼" × 1" (4) + unions–€50
VC8015 coupling, raised stand, gravel soak-away–€55(V13)
28 mm pipe, fittings, insulation ≥ 30 mm–€280
Shipping DE/LT–€80
Total materials≈ €2,705all-NL ≈ €3,385
ISDE subsidy (heat pump only, code KA29000)− €2,125heat pump bought Dec 2025 → 2026 rules

Not included: the installation company's labour, the optional drinking-water expansion vessel (€40–60), floor-heating phase 2 (≈ €175–540). Already in the boxes: Y-filter, 3 sensors, controller, ATW-A03N, 6 rubber dampers, drain elbow (Haier); T&P valve (WT200V); magnesium rod (WT60V).

Planning: 3–4 quotes this week. Order tank and buffer as soon as an installer accepts customer-supplied Haier tanks. Other parts before ≈ 10 November. No delivery date before ≈ 20 November → Dutch fallback. Goal: warm before 20 December.

9. All open points in one table

What no Haier document settles. Points with a question number are on the forum; the rest I settle myself or with the installer.

#UncertaintyHow to settle itQuestion
1Tank sensor input CN50 or CN48One input, check that E10 doesn't appearV1
2Setting so the BDR91 on CN13 worksThird party, Type 2; testV2
33-way valve direction (K during DHW?)Valve with reversible rest position; test with pipe temperaturesV7
4Pump 1 setting, pump 2 during DHWRead the flow; watch pump 2V4
5DHW window via ScheduleTry it; otherwise timer on CN47V5
6Which element thermostat is adjustableLook under the element coverV10
7XMvK/YMvK as "equivalent" of H07RN-FInstaller decides (NEN 1010)V11
8HomeWizard pulse outputProduct data; otherwise Eastron SDM120V6
9Floor heating: floor, loops, oxygen barrierFormer owner; read the pipe printV8
10Radiator output at 45–55 °CJaga type stickers; ISSO 51V12
11Sensor diameter vs. pocket/portMeasure when the tanks arriveV9
12BDR91 contact suitable for pump 2 (fallback)Datasheet; otherwise a small relayV3
13Prices of 20 A RCBO, insulation, standShopV13

10. Solar panels vs. heat pump (simulation)

Hour-by-hour simulation of an average year with the real monthly yield (5,520 kWh), KNMI climate normals for the region, 3,470 kWh space heating and ≈ 1,195 kWh tap water:

  • Heat pump ≈ 1,600 kWh/year, ≈ 75 % of it in November–March.
  • Heating the tank between 11 and 15 h: 627 kWh (39 %) directly from the panels, against 305 kWh when heating in the evening. Hence V5.
  • Net metering (saldering) ends on 1 Jan 2027, so direct self-consumption becomes more important.
  • In December/January the panels cover only 15–20 % of the heat pump.
Solar yield vs. heat-pump use per month
Simulation per month.

11. Photos and drawings

12. Reply template

Want to help? Copy this template, paste it into your reply in the forum thread, and fill in only the questions you know something about. Just delete the rest. That way I can find the answers per question. Many thanks in advance!