Boiler pressure on EcoTec keeps rising

[Jimbo376]

Hi All, I have a problem with my 10 year old EcoTec boiler. The pressure keeps rising to over 3 bar every few days. To get it running again I am releasing about a cupful of water from a radiator to get it below 3 bar. The filling loop is disconnected and I’ve noticed water from the pressure relief valve. Where is the water coming from? Any ideas please.

 

[Last Plumber]

Which ecoTec?

It could be via a secondary heat exchange of some sort. e.g. coil inside a cylinder?
Depends on the installation you have.

 

[Jimbo376]

Which ecoTec?

It could be via a secondary heat exchange of some sort. e.g. coil inside a cylinder?
Depends on the installation you have.

EcoTec plus 624 as part of a sealed system with large hw cylinder.

 

[Last Plumber]

EcoTec plus 624 as part of a sealed system with large hw cylinder.

Could be a hole in the coil. If the water pressure (I'm presuming unvented mains fed cylinder) is higher than the heating system, it will rise to equalize.

A Plumber will be able to diagnose whether that is it or not. If it is, you will need a new cylinder. Don't get one too big, there's no point.

 

[Jimbo376]

Thanks for your help I’ll get a plumber to confirm your diagnosis and sort it out.

 

[John.g]

What is the boiler pressure with a cold system?.

 

[Jimbo376]

I’m only releasing a little water to get it below 3 bar, probably should get it down to 1.5. To answer your question it will stay above 3 (3.4 is the highest I’ve seen) until I release the pressure, boiler automatically cuts out when too high. I first noticed this when the hot water went cold, the boiler had a fault code (can’t remember the code) and the pressure was high, resetting and releasing pressure got it going again. The tank is a Stelflow 210L

 

[John.g]

You might have a EV (expansion vessel) problem, it may have lost or partly lost its precharge pressure, suggest reducing the cold pressure to 1.5bar, it certainly won't take 3 days to rise to 3bar on system reheat if this then is the problem.