Central Heating Leak

BobMc

Hey Gang,
have a wee problem with central heating loosing pressure.

So here's what I know -

System recently serviced, needed new expansion vessel (was about 7yrs old the old one) - also replaced was Pressure Release Valve which was dripping
i Knew all this towards end of last heating season (July wasnt it )

So had serviced in plenty of time before winter.

Going back about 9yrs or so when original boiler was repalced (house built 2000 or so, we're second owners) we discovered there was leaks in system in pipes on ground floor, We hired a guy with an Heat Seak Camera found one and repaired it, with suspicion of 2nd location but couldnt locate it. I'm guessing over time this 2nd leak has grown or perhaps others !

We'd normally just top up every couple weeks or maybe month which I know is not good for system or boiler but we'd no option really.

Problem now is its needing fresh top up more often and its compounded by the recent poor water pressure in our area which has turned so bad there's not enough pressure in the mains water to pressurise the system enough for it to come on.

Any suggestions anyone can offer. A good leak and fix company, a better way to pressurise the system, we've to try time the repressurising of boiler now to late at night etc when there's hopefully enough pressure available.

On top of this our mains pipe leading to the house is very prone to freezing and it does so very easily, We've been caught out before where mains has frozen and no water to pressurise system, had to move into my folks house

We're getting desperate with the winter approaching

Dtp1979

Oil or gas boiler?

BobMc

Gas !

Dtp1979

BobMc wrote: »

Gas !

Ideally if you can source the leak then do. Check the pressure relief valve isn't dripping. Check the coil in the cylinder isn't leaking either. I've seen this a lot

BobMc

Yeah, pressure realease valve is brand new, so all good, "coil in the cylinder" would plumber who did service have checked this.

Ideally we know we need the leak fixed, but its trying to find someone reliable to find it and fix it without digging up the entire ground floor !

Dtp1979

BobMc wrote: »

Yeah, pressure realease valve is brand new, so all good, "coil in the cylinder" would plumber who did service have checked this.

Ideally we know we need the leak fixed, but its trying to find someone reliable to find it and fix it without digging up the entire ground floor !

You'd have to drain the heating and pressure test the coil on the cylinder. They often leak

BobMc

is that coil located inside the hot water cylinder? I've no clue, if its inside the hot water cylinder would that make the hot water very hot coming out of the taps?

Dtp1979

BobMc wrote: »

is that coil located inside the hot water cylinder? I've no clue, if its inside the hot water cylinder would that make the hot water very hot coming out of the taps?

No. it'd only be a tiny pinhole so would have no effect that way you describe

BobMc

have a builder coming in next few days for look at fresh mains water instal, his plumber is going to do some investigations re leak in heating too

Dtp1979

BobMc wrote: »

have a builder coming in next few days for look at fresh mains water instal, his plumber is going to do some investigations re leak in heating too

Keep us informed

Tom44

Have you tried adding leak sealer liquid to your system ?

BobMc

A plumber did once, didnt have much success on the leak at the time as too large, might be worth another shot too though but I've not heard best things about them

Dtp1979

BobMc wrote: »

A plumber did once, didnt have much success on the leak at the time as too large, might be worth another shot too though but I've not heard best things about them

If you add oxypic into the heating system it'd seal the leak, but better still, if the coil is leaking then the hot water will appear browny in the taps. This is a sure fire way to confirm the coil is leaking

K.Flyer

You really need to disconnect the flow and return from the cylinder coil and cap the pipework. You can use the immersion to heat the water for the duration.
If the coil is leaking, your heating system pressure will remain stable after being disconnected and re pressurised. If the pressure drops then its time for the oxypic as long as you have ruled out everything else.

Rojomur

Ill just add my bit to this. I had similar leak since the system was installed 4 years ago.it is a Baxi megaflo compact gas boiler. It was a small leak and initially only required topping up twice a year which i was told was normal but this increased to nearly weekly up until a month ago. I suspected a pinhole leak somewhere on the ground floor as there are no visible wet patches anywhere...Parts were replaced 6 months ago under warranty by Baxi as a visible drip was coming from inside the machine. That didnt solve the problem and 3 months ago a baxi engineer replaced a different part. The slow water pressure continued to drop albiet slower...but i still suspected a pin hole leak somewhere... one plumber quoted €100 to put in a leak sealer so i decided to give a try myself....anyway after loads of research i settled on Plumb 7 from heatmerchants...around €20. I drained around 3 litres from a lower rad and added the Sealer in the upstairs bathroom rad. Refilled up to pressure and ran it through. Around 3 days later i checked again and pressure had dropped to under 1 bar and my heart sank but logically i thought it might take time for the leak to seal so i topped up again and lo and behold pressure loss has stopped.������ so i think its worth a try before any expensive options are tried.

BobMc

Quick Update, Plumber been out and discovered a couple things, the pressure release valve that was replaced was installed in the incorrect place (attached to overflow pipe outside back door) small drip up underneath boiler (related to pressure release valve) the filling loop (attached to it is an old auto fill valve that was used by original owners) is also dripping but below a tap used to top up. So he also checked expansion vessel which seems Ok,

Plan of action is to to the replace the pressure release valve, he's going to remove the old auto fillng valve and set up a new filling loop with easier access, and we'll start again, perhaps then adding some leak sealer to elimnate any pinhole leak,
still awaiting builder to quote for replacing the mains pipe coming in which is easily prone to freezing

BobMc

Small Update,

well gang been a busy few months, plumber has done the remedy works before christmas, still loosing some pressure but slowly and a leak sealer will be added later this month as both he and us are busy,

also had my new deeper water mains installed, bloody discrace how far down it was, all because of self regulation