Vaillant ecotec pro 28 losing pressure

[SteepLearningCurve]

Hello,
Here is my situation: I have a Vaillant Ecotec pro 28 combi boiler that is about 6 years old. It is stored in the loft of a 3-bed house and until now I've never had any problems with it apart from a small amount of pressure loss which is so gradual I only needed to top it up every few months or so. I do this using the 2 valves underneath boiler as instructed by a plumber friend. A couple of weeks ago I switched the heating on (after it being off all Summer) and since then the pressure has been dropping pretty much every night so that in the morning there is an F22 fault code and the heating doesn't come on. To get around this I have been adding pressure as before and then the heating works again.

The only other thing to mention is that before I switched the heating back on again (after the Summer) I added some pressure but accidentally added way more than normal until it was pretty much in the red. My worry is that i did some damage that day...

Anyway, so far I have had a quick look at all the radiators and pipe joints and can't see any visible leakage.

Are there any other things I can check/test for myself before calling out an expert?

Many thanks to anyone taking the time to read this and hopefully respond.

Cheers

J

[Razor]

Set the pressure to around 1.2 with the boiler cold then run it for 30 mins and let us know what the pressure is then. Almost certainly a flat expansion vessel on one of these.

Btw

[SteepLearningCurve]

Hi,
Many thanks for the swift reply.

So I filled the pressure back up to 1.2 whilst cold and then run the heating for 30 mins. The pressure is now reading 2.7.

Does that mean a flat expansion valve?

Can i fix this myself?

Cheers
J

[Razor]

It's pretty simple on that beast if you have a footpump with a decent gauge.

Firstly turn the power off to the boiler.

Next attach a hose to a drain off somewhere on the heating system and open the valve, leave it open until the water stops coming out.....

Leave the drain off open and pop the front cover off the boiler. Now don't touch anything except for the red expansion vessel down the right hand side, looks kind of like a metal hot water bottle!!

You should see a schraeder valve on it - don't let the name panic you it looks just like the ones that you pump your car tyres up with

Pop the pump on and check/adjust the pressure until it's reading 0.8 bar (or around 12psi in old money), as you do this some water will come out of the hose that you left on the open drain point. It's supposed to do that!

Cover back on and drain point closed then refill the boiler to 1.2 bar.

Finally power back on and run it for 30 mins. If you're lucky it's all fixed, if your not the pressure relief valve will be dripping but we can sort that if we have too

[SteepLearningCurve]

Thanks for the detailed response. I can see the valve and have a bike pump with pressure gauge so hopefully that will suffice.

The only bit I'm not 100% on is when you say 'attach a hose to a drain off somewhere on the heating system and open the valve'.

Could you lay that bit out in simpleton terms?

Cheers

[Razor]

Have you got any valves - probably under the radiators or boiler that can be used to empty the water from the rads?

You don'r need to drain it all out but you do need to leave a drain valve open or you won't be able to pump the expansion vessel up properly, you'll get a false reading

[SteepLearningCurve]

Aah, ok. I'm with you. I definitely have one on a radiator downstairs so could use that. How much water would you expect to come out?

Cheers

[gas4you]

Oh dear Razor, Mr gas policeman Tony will be along soon to say you shouldn't remove the front cover of this unless registered!!

[thescruff]

Oh dear Razor, Mr gas policeman Tony will be along soon to say you shouldn't remove the front cover of this unless registered!!

Tony's on a course so all is well.

[SteepLearningCurve]

As expected it was a flat expansion vessel. So i followed all the instructions and now everything is working as it should. 2 days running the heating and no loss of pressure over night.

Amazing!! So pleased and also scored major kudos with the wife :)

Thank you so much for the advice.

Cheers

J

[Razor]

Thanks for the update. It's easy when you knew how isn't it