baxi 105e instant combi losing pressure

[grajam247]

I have a Baxi 105e instant combi boiler that loses pressure once the central haeting has switched off.Is there a few causes for this or is it likely to be a leak on the heating circuit.I normally have to recharge the pressure every one to two days.
regards
grajam247

 

[gas4you]

Whats the pressure reading when the ch is on and hot?

If 3 bar or over could be the prv is operating and letting water out.

If this is the case check expansion vessel pressure, see FAQs.

Check there is not a constant drip from the prv.

Pressurise system, isolate at flow and return valves, leave as long as possible, if no pressure drop then leak is on system.

 

[Agile]

Expansion/storage vessel is failed.

Usually happens to all these after 2-3 years!

How easy to change depends on the flue position and how it has been fitted.

Can require boiler coming off the wall!

Tony

 

[grajam247]

Many thanks for the above info guys.Opened up boiler today and located the expansion vessel.Pushed in centre pin of shraeder valve and water came out straight away.Does this mean that the exp.vessel is definately shot.
regards
grajam247

 

[baxpoti]

Many thanks for the above info guys.Opened up boiler today and located the expansion vessel.Pushed in centre pin of shraeder valve and water came out straight away.Does this mean that the exp.vessel is definately shot.
regards
grajam247

Yes it does!

 

[ChrisR]

Most common solution is to fit an external pressure vessel when that happens. Not a big deal as long as you have somewhere to put it. Sometimes you can just lob them on top of kitchen units, or under a plinth. £150 or so should cover it.
Silver lining is that your store of hot water will be bigger than it was when the boiler was new!