Vaillant
Vaillant 20-plate DHW heat exchanger 178973
At a glance
- Also known as VAILLANT178973C
- Installation and commissioning must be carried out by a Gas Safe registered engineer
£70.80
£59.00 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The 178973 is Vaillant's 20-plate domestic hot water (DHW) heat exchanger, fitted to the ecoTEC Plus range of combi boilers. It sits on the secondary side of the plate assembly and transfers heat from the primary circuit into the water drawn off at taps and showers, keeping the two circuits separate.
Signs this part needs replacing
- Hot water runs lukewarm or fluctuates in temperature while the central heating still works normally
- Reduced hot water flow rate at taps and showers
- Boiler cycles or locks out specifically when hot water is called for
- Kettling or knocking noises from the boiler during hot water use, often a sign of limescale build-up inside the plates
Before you order
- Match the part number 178973 printed on your existing heat exchanger before ordering
- Confirm your exact boiler model and revision (R1/R3) and GC number, as ecoTEC Plus 824/831/837 span several data plate variants
- Have the system flushed and treated for limescale/sludge where hard water is likely, to protect the new part
- Installation and commissioning must be carried out by a Gas Safe registered engineer
Compliance
| Alternative numbers | VAILLANT178973C |
|---|
No fitment data held for this part.
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