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.

Having to keep a close eye on it is an irritation, and 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".

 

[maul]

unlikely to be the underfloor pipes if its just started to happen and nobody has done any diy etc near the pipes where they are buried in the screed so somewhere you have a leak and its most likely a connection.
carefull visual inspection of every pipe and fitting is needed. if there is a leak it will show as corosion (green) on the copperwork.
sometimes you need to put your fingers around the back of the fittings /manifold etc to see if you can feel any wetness.unfortunately hot pipes will dry out some of the water as it leaks making it a bit harder to find
also check presure relief valve where it goes out of the building is it dripping ?
if it is or if you cant find anything obvious then its get the engineer out time as it could be in the boiler itself.

 

[Matty2806]

the slightest weep would be enough to drop the pressure at that rate check every fitting

 

[moorfield]

Thanks.

Two things I've spotted this afternoon.,

1. The pressure guage reading on UFH manifold is fine, so I don't think its that, and is on the boiler side.

2. There is a very tiny amount of water weeping from the joint where the cold water mains comes into boiler - presumeably that might be it ?

 

[maul]

the pressure in the ufh and the boiler is the same thing.

the water in the cold mains is seperate to the water in the heating circuit.

its the cold main you are using to fill the heating circuit when you top it up.
keep looking sorry :S

a good tip is to use a piece of tissue paper preferably not white to wipe around hard to see joints
the paper will change colour when wet and is easier to see (the white stuff doesnt change colour so much)

 

[moorfield]

the pressure in the ufh and the boiler is the same thing.

sorry don't understand? - there is a heat exchanger between boiler & ufh so they are separate circuits? pressure on ufh guage definately looks ok

the water in the cold mains is seperate to the water in the heating circuit.

its the cold main you are using to fill the heating circuit when you top it up.
keep looking sorry :S

fair enough, but still don't like the idea of the cold water mains joint leaking, but ill keep looking...

 

[ecowarm]

Ok your underfloor is seperated from the heating circuits by a heat exchanger so if the boiler is loosing pressure its someware between the boiler and H/E or in the boiler

the leak on the cold water may just need a compression nut nipping up

 

[moony]

is the pressure relief valve passing?

 

[maul]

i didn't realise you had a heat exchanger in your system

obviously you need to fix the mains leak but i meant thats not what is causing your pressure drop. sorry for the confusion i caused

 

[stevetheplumber]

a heat exchager on under floor ive never seen that ?