Leaking central heating system ?

50Twuncle

We appear to have a leak in the piping in our central heating system - we have to top up the boiler every week at least
Is there a way of discovering where the leak is - without lifting all the carpets and floorboards through-out the whole house ?
There is no sign of any water stains on the first floor ceiling - so I am assuming that the leak is downstairs
Alternatively - could the problem be with the boiler - a 5 year old combi Worcester ?
Could it somehow be "boiling off" the water - there are no physical leaks on the boiler itself .........??

macman

Make and model of your boiler would help.
First check the PRV overflow pipe outside-is it discharging?Or you may have an underpressurised or faulty EV. The last possibility is a leak on the CH circuit, you can check for leakage at the rads without lifting anything. But check the first two points before that. A small leak won't necessarily show, as it will evaporate before you see it.
No, it can't 'boil off' water, a combi is a sealed system.

50Twuncle

macman wrote: »

Make and model of your boiler would help.
First check the PRV overflow pipe outside-is it discharging?Or you may have an underpressurised or faulty EV. The last possibility is a leak on the CH circuit, you can check for leakage at the rads without lifting anything. But check the first two points before that. A small leak won't necessarily show, as it will evaporate before you see it.
No, it can't 'boil off' water, a combi is a sealed system.

It's a Worcester Greenstar 28i Junior
Incidentally, and I assume that this is linked - it does need pumping up annually - is there is a leak in the PRV ?
I assume that this means a new PRV ?
How much are these ?
It does drip water from the condensation pipe - but I assume that this is normal ?
There are no obvious leaks at the rads themselves - no stains on the carpets etc.....

WillCalderwood

Is your heating system zoned? Can you isolate sections of the system to see if the leak still occurs?

You'll almost certainly be able to isolate the boiler, so you could switch the heating off for a couple of days with the boiler isolated, then re-open the valve and see if the pressure drops. Wait for summer. :-)

50Twuncle

WillCalderwood wrote: »

Is your heating system zoned? Can you isolate sections of the system to see if the leak still occurs?

You'll almost certainly be able to isolate the boiler, so you could switch the heating off for a couple of days with the boiler isolated, then re-open the valve and see if the pressure drops. Wait for summer. :-)

Sorry - no the whole system is connected in one loop.
But - when the heating is not being run - the pressure stays as it was previously
When you say "re-open the valve..." - which valve ?
The filling loop is permanently connected - so if I open the filling valve - water will flow in.....

50Twuncle

Could it be a faulty expansion vessel ?
How much do these cost to replace ?

MoneyMate

Might be worth having the boiler itself checked for internal leaks first, I have a Greenstar 30 which three weeks ago started leaking, it was found to be a simple union that had come loose after 2 Years.
For obvious reasons a professional only should do this task :beer:

GOOD LUCK, Hope it's something simple & cheap.

50Twuncle

MoneyMate wrote: »

Might be worth having the boiler itself checked for internal leaks first, I have a Greenstar 30 which three weeks ago started leaking, it was found to be a simple union that had come loose after 2 Years.
For obvious reasons a professional only should do this task :beer:

GOOD LUCK, Hope it's something simple & cheap.

The boiler is mounted on the kitchen wall - not in a cupboard - and it doesn't show any signs of any leaks (no water stains/rust or similar) - so I am guessing that it is not a physical leak as such - I am assuming that it is the expansion vessel/prv ?

diywhynot

Last service? If the EV needs replacement then can be a v. expensive repair. See Section 32 in your manual for details.

keystone

EV on these is internal hence DYN's comment about cost. IF its a dud EV then the simplest repair is to fit an external one on the system.

When you say the condensation pipe do you mean the condensate pipe which will be a white plastic pipe and is supposed to discharge or do you mean the short length of copper pipe that also comes out of your wall. The latter is the Pressure Release Valve outflow. If that is driping then the PRV has lifted at some stage due to excess presure in the system. They never reseat properly due to getting full of carp when they operate and so they pass, you lose water and the pressure drops. If you are not sure about that then tape a plastic over the end of the pipe. If it gets water in it then the PRV is passing and needs attention.

When was the beastie last serviced? If its due soon get your RGI to chack the PRV.

Cheers

anotherbaldrick

keystone wrote: »

EV on these is internal hence DYN's comment about cost. IF its a dud EV then the simplest repair is to fit an external one on the system.

When you say the condensation pipe do you mean the condensate pipe which will be a white plastic pipe and is supposed to discharge or do you mean the short length of copper pipe that also comes out of your wall. The latter is the Pressure Release Valve outflow. If that is driping then the PRV has lifted at some stage due to excess presure in the system. They never reseat properly due to getting full of carp when they operate and so they pass, you lose water and the pressure drops. If you are not sure about that then tape a plastic BAG over the end of the pipe. If it gets water in it then the PRV is passing and needs attention.

When was the beastie last serviced? If its due soon get your RGI to chack the PRV.

Cheers

BAG added !!!!!!