Mystery leak in unvented heating system

[banplumb]

Hi all,

Newbie here. Not good way to start

I've a Vaillant ecotec and pressurised cylinder too. Just had plumber isolate the
cylinder and still losing pressure around 0.2bar over 12 hours. Been many months.

Started losing all pressure in a day recently, over time was getting worse.

Boiler insurance changed many parts deemed necessary while troubleshooting.
Then isolated it and it's not losing pressure.

No visible signs of leak in house so presume downstairs.

About to spend a load of money getting leak buster's in any recommendations on these guys?

Is it worth putting air at pressure into system and listening
For hissing?

Once system is sorted will turn to the cylinder...

Thanks
B.

 

[AMGasServices]

Welcome.

Why don't you ask the boiler insurance company to have a look at it with a thermal imaging camera as it will be a more cost effective way of tracing a leak.

 

[banplumb]

Welcome.

Why don't you ask the boiler insurance company to have a look at it with a thermal imaging camera as it will be a more cost effective way of tracing a leak.

Oh! I will ask. But they have eliminated the boiler already.
They are Domestic and General.

Is there should reason you say they will do a leak check with
a thermal camera of they have eliminated the boiler? The rest of the
Heating system is not covered AFAIK.

Thanks
B.

 

[Last Plumber]

Obviously, different people will have had different experiences with thermal imaging cameras.

I have used them to try and find leaks in commercial buildings due to the inconvenience of lifting floors.

Unfortunately, it was not effective, it shows partially where pipes run but dependant upon the ground or surroundings that the pipe is in, you cannot necessarily see a leak.

The thermal imaging search can be extremely expensive, especially if nothing is found.

Just to repeat, I am only speaking from my experience and others may well have found it useful.
It must work well in some cases otherwise it wouldn't continue to be of use.


I would start by pressure testing the pipework if you cannot get underfloor to see physically. If you have ruled out the cylinder and boiler, it is highly likely that the pipework is leaking.

 

[Scott_D]

What model vaillant? System or heat only
Some pics might help

 

[banplumb]

Thanks guys for taking the time. Bit the bullet. Got leakbusters in. Very costly, but found a leaking radiator! It's a column radiator almost 10 years old. No water was visible. But their gas detection showed it up.

Since shutting off the rad. Pressure has been steady for 4 days now.

So my advice to anyone is isolate each rad 1 by 1 watching for pressure loss with each change. Give it enough time.

Phew!

B.