How to find a leak

[Pulga]

We have been having a problem with the central heating system recently and it's getting worse, so I decided to ask for help.

To summarise the issue:
Boiler Vokera Compact SE 28
Closed circuit.
Losing pressure to the point the boiler is not starting until the circuit is topped up. This is now an operation that needs to be done daily. The pressure is lost whether the heating is on or off.
We have checked every radiator in the house, and every valve. We have replaced any radiator that seemed too old, and all the valves in the house.
We have brought in a specialist to check the boiler and this has passed fine.

So the only obvious cause is : there is a leak somewhere.
We can't see any water on the ceiling. So we assume the problem is not at the first floor, or we would see a wet patch somewhere after so many days. We looked under the floorboards near each radiator at groundfloor level, and it's all dry.

Could you please advise on any method that we could use to find this leak. Ideally something a little bit less destructive than tracing every pipe in the house through floors and walls. Any specialist services we can engage to help us find it. Any advice much appreciated.

 

[Slugbabydotcom]

Have you checked the Pressure relief pipe outside?

 

[EliteHeat]

And once that has been done, bung some leak sealer in.

It might work and it might not, but it's a cheaper first option than replacing radiators, valves and getting a specialist in to 'pass' the boiler.

 

[Pulga]

Have you checked the Pressure relief pipe outside?

Yep, no drip or anything from there.

And once that has been done, bung some leak sealer in.

The plumber suggested this, but he said it may damage the boiler. Will check with Vokera after the holiday period, and if they say it's alright, will give it a go. As you say, it's a lot easier.

But in case it doesn't work, any idea what's Plan B?

 

[EliteHeat]

Why on earth would it damage the boiler? it's more likely to do absolutely nothing and make no difference to your leak.

 

[holty]

check the aav these are prone for leaking. a way of testing to rule out the boiler is isolate the flow and returns.

 

[bengasman]

look for compression joint under the floor

 

[Pulga]

Guys thank you very much for all the suggestions.

So far we tried Fernox F4 - nothing happened

Tried another suggestion found on this site and put about 200 ml of concentrated aftershave in the system and hoped it will stick somewhere. This was a complete fail since it didn't smell anywhere. How much water is in a central heating system (4 bedroom house, with about 9 radiators)? We need to top up every day now with about 3 pints.

I dare say I don't know what an AAV is, or whereabouts should we look for compression joints?

Will try with a higher concentration of aftershave (bought the smelliest counterfeit I could find in the market) but if all this fails, can you suggest some specialists who have the appropriate equipment to find a leak, and deal with domestic customers?

Thank you. The situation is getting a bit desperate

 

[bengasman]

you could call in a pro.
the aftershave was dodgy, the next stunt could cause serious damage

 

[Pulga]

you could call in a pro.
the aftershave was dodgy, the next stunt could cause serious damage

Could you please qualify that statement. How would this create serious damage.

 

[numpty1]

after shave was designed for the human face not boiler internals,it could be possible that the aftershave could react in the boiler and cause damage.

 

[bengasman]

NEXT stunt
if you can dream up aftershave as as a way to find a leak....................

 

[numpty1]

NEXT stunt
if you can dream up aftershave as as a way to find a leak....................

ben don't knock it untill you try it

 

[Softus]

check the aav these are prone for leaking. a way of testing to rule out the boiler is isolate the flow and returns.

You haven't told the whole story though, have you.

If the valves don't hold up then you'd be none the wiser, so after isolating the boiler you have to relieve the pressure from a rad and then see if the pressure holds.

 

[BOB D.O.L.E]

NEXT stunt
if you can dream up aftershave as as a way to find a leak....................

Try filling it with shaving foam hee hee hee.................