Combi + UFH manifold, losing pressure daily

[moorfield]

The situation:

An Ariston Microgenus HE 24 connected to a Kee Triple Tube UFH manifold.


The problem:

Boiler is regularly losing pressure, we currently have to refill it to 1-1.5 bar every 3 days or so, and if we forget we'll eventually get the E02 error.

Not a problem, just an irritation, but I'm concerned it's going to get worse not better over time.

This question is slightly different to the usual Microgenus/E02 ones that appear - I'm wondering where the pressure leak is most likely to be - in the boiler or could it be the UFH manifold somewhere?
Are there any easy checks I can do/try on the boiler - to eliminate that from enquiries?
If I call out my Ariston guy is he likely just to turn up and say "No can do, its somehwhere in your UFH mate".

 

[bengasman]

Not a problem, just an irritation, but I'm concerened it's going to get worse not better over time.

It is a problem.
Constant adding of new water will lead to corrosion which will eventually kill your boiler.

If I call out my Ariston guy is he likely just to turn up and say "No can do, its somehwhere in your UFH mate".

Quite possible

 

[moorfield]

Edit: Actually I've just realised there's a pressure guage on the UFH manifold which has always been a steady 1.5ish.

So I think I've answered my own question - its the boiler. Ho hum.

 

[mysteryman]

Not necessarily. Are the underfloor and the boiler on the same sealed system? If so, both gauges should read the same, give or take. A gauge that is dropping and rising as expected is more likely to be correct than one which never moves. The non-moving one may have a blocked entry port, or some other failure. You need to find the leak. Tie a plastic bag over the pressure relief valve outlet with an elastic band. Check it for leaks after 24hrs. If it lets by at all, you need a new prv, and get the expansion vessel checked for a ruptured diaphragm or low pressure on the air side. You must not carry on as you are, because it will ruin any cast iron or steel parts in your heating, as well as causing sludging.