Boiler Pressure Dropped from 1.5 to 0.2 in a Month

[adzyp]

Morning All,

Woke up this morning to a cold house and heating wasn’t on after 7am as scheduled. Checked boiler (Vailant EcoTec Pro) and error F.22 was flashing and pressure was at 0.2 bar. Topped up with filling loop to 1.5 and it went back on its way.

Now to add a bit more context, back at the start of December I just happened to notice the boiler pressure was down to 0.7bar so topped it up to around 1.3/1.4 I think it was. I then kept an eye on it for a few days and the pressure seemed to remain stable and no heating issues so I forgot all about it until this morning.

Not had chance to check for any leaks yet, will do that this evening but certainly not noticed anything obvious around the radiators so will check them all closely and will pop the front of the boiler later to see if there’s anything obvious.

Can anyone offer any other suggestions?

Given that its lost just over 1 bar in a month would this be classed as a ‘slow’ leak and does it indicate something else like a faulty part inside the boiler rather than a pipe leak? Maybe a system flush?

I’m quite handy with things so happy to tackle anything within the usual safety limits of course.

 

[Jajodu]

Check the pressure relief valve outlet to see if it's wet.

 

[adzyp]

Check the pressure relief valve outlet to see if it's wet.

Ok, will be difficult without a ladder in the dark but will see what I can do later

 

[Jajodu]

You can tie a plastic bag over the outlet and see if it fills up. Another thing that can cause pressure variations is the expansion vessel needing recharging with air. There's a how to section on the method in the FAQs

 

[adzyp]

You can tie a plastic bag over the outlet and see if it fills up. Another thing that can cause pressure variations is the expansion vessel needing recharging with air. There's a how to section on the method in the FAQs

Ok ill give it a go, thanks. If it does turn out that water is coming out of the relief valve, what is the diagnosis?

 

[Jajodu]

Depends on how confident you are in your abilities, it's usually best to replace it it it's leaking. Not a difficult job.

 

[adzyp]

Depends on how confident you are in your abilities, it's usually best to replace it it it's leaking. Not a difficult job.

Ok, so got home first thing ive done is take the front off the boiler and noticed that there seems to be some dried rusty coloured stains in the bottom and what still appears to be a small patch that is still wet (circled green in photo). Not sure if this is the cause of the problem or something separate?

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[adzyp]

see next post

 

[adzyp]

Ok, so yeah the diverter valve is definately leaking, albeit very slowly. Can get a refurbed piece for £35. How much of a task is it to replace?

 

[Jajodu]

Depends on how competent you are at this sort of thing. Looks straightforward, mains water off, boiler off and isolated, drain the boiler, remove and replace.
Plenty of you tube videos on replacing one of these.

 

[muggles]

Standard Leakotec issue there. BTW you shouldn't be removing the cover of your boiler unless you're Gas Safe Registered - it forms the safety room seal and should only be removed and refitted by people capable of carrying out the 26.9 regulation safety checks.