Our DIA 20 combi boiler, about 10 years old, has become slow to detect mains water flow, ie we run the "hot" tap for ages before boiler activates. Then, once it has primed, it works OK. This response delay has been building up over the weeks. If tap is not used again for a while, same slowness thing occurs.
The filling pressure from the filling loop is OK, and CH section works when asked for heat.
Is there such a device as a flow detection valve that needs replacing?
TIA
If it has a pressure activated 3-way valve then this is most likely the problem. If it has an electric 3-way valve then the flow switch is most likely the problem.
Thanx Doctor What does this gismo (either sort) look like? Describe it if poss. I need to know what to search inside its gubbins for, bnot knowing which valve. Would it be directly in the mains water path? Is it a 3rd party part, or -must- it be obtained from Ariston's importers (they only sell to registered plumbers, I believe). And I guess the mains c*ck has to be turned off during replacement. Jim
I haven't got a manual for this model. However other models and these sypmtoms suggest that it is likely to be a rubber diaphragm operated type.
The usual failure mode is that the rubber has a small tear in it and it reduces it sensitivity to water flow. Typically the component is circular
50-100mm diameter.Have something to add? Share your thoughts — no account required.
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