Tracking down a central heating system leak

JJS400

Just found this thread and trawled through the lot in the vain hope of finding answer. Alas feel despair - am locked into this Kafka-esque nightmare with Homeserve...
1. Feb this year - boiler (Ideal) starts losing pressure
2. 14 visits later, with boiler engineers and plumbers (a) Denying it's happening then (b) Blaming the other, it's still going on
3. Boiler has been almost completely rebuilt. Secondary heat exchanger replaced. Primary heat exchanger replaced - twice (first one they fitted was faulty! Unbelievable). Pressure gauge replaced. No water out of pressure release valve/vent (though it was damaged by one of the engineers). Boiler serviced.
4. Thermal camera revealed nothing in the pipework - except the heat of a suspended halogen lamp in a room below. For which I pulled up floorboards and damaged them. Guy was supposed to be doing full leak test - but his "van was in the garage".
5. Boiler settled down in the summer when the heating was off. I got significant compensation from Homeserve for the fiasco. Hoping that the problem was solved by the second heat exchanger replacement.
6. Then when it came on again in October - its now failed 5 more times. No pattern. It can hold for 2 weeks then fail. Or fail twice in one day. Baffling.
6.Now trying...and trying...and trying to get a proper leak test done of the pipework. Homeserve have been terrible again. Not returning calls, information not getting through. Every time I call I have to start all over...now months and months of it. Today the plumber turns up - supposed to do a full leak test. No equipment, no idea what the job was. As usual.

I cannot think that it can be anything but a slow leak in the pipework somewhere. No obvious signs, but it's a real worry. I am coming to the point when I am going to have to abandon Homeserve and pay for it all to be checked separately - but am terrified of the cost. What are my options though? And what sort of test - gas, air, water?? Many pipes are buried (though not in concrete at least) or inaccessible behind cupboards etc.

LRoss

Try your home insurance- ours covers Track and Trace for leaks?

thescouselander

I've been going round our heating system fixing a load of leaks. Basically we had an open system that was original to the house and when we replaced the boiler with a closed system it started losing pressure. So far all of the leaks I've fixed have been leaky lock shield valves or leaking blanking plugs on the radiators.

In both cases there was not much to see except for some staining/corrosion near the leaking component. Most of the time I couldn't see any water but if I covered the suspect area with a piece of foil I could clearly see water condensing on it - that is the water was vaporising before it could develop into a drip.

I'd say definately check valves and seals first and look out for clues like rust etc. I'm pretty much on top of the leaks now with hardly any topping up required.

The_Mac

Following the installation of wet underfloor heating, screeding and porcelain tiles, my boiler pressure was dropping to zero and I had to top it up with water twice a day. The plumber tried to find out the cause, which was eventually narrowed down to one of the loops in the underfloor heating, covering an area of 3 x 7 square metres. After researching, I found a leak detection team on the Moneysavingexpert forum. Andrew Slater, Director of The Leak Team, based in Newcastle but with nationwide coverage, visited me today. Using a thermal imaging camera, an acoustic 'Elephant's foot' and Hydrogen gas, he was able to pinpoint the leak to an area of less than 6 inches square. Only 2 tiles were lifted and the Ditramat and screed carefully removed. The cause of the leak was a sharp stone from the screed. Now it just has to be fixed! I highly recommend The Leak Team!

Eccles01

Just thought I would dive in with my recent experience (Vaillant Ecotec Plus 618):- Started having pressure drop requiring top up around 18 months ago. Initially it would go around a month before requiring another small top up. Began to suspect a small leak, but unsure after nearly ten years faultless performance. My gas man did all the usual checks and ultimately a full system flush and refill (not cheap but after ten years, probably needed it anyway. My gas man is usually very knowledgeable and not a rip off merchant as so many are so refused to charge me until he knew it was right. After about a fortnight it started again so after a quick phone call back he came again and checked everything out again. I said I was prepared to have the floorboards up and start searching for leaks but he said "Why should a leak occur after ten years without problems?" He wanted to try one more trick - replace the pressure monitoring device. Well folks that was about a month ago and so far the pressure is staying put at 1.2 BAR so no leaks just a faulty pressure device it would seem. Think I will give it another couple of weeks then happily pay him the £300 he wants for all his calls and work. No I can't give you his phone number, he has more than enough work already as you might expect. Feel sorry for all you guys who get ripped off by over pricey tradesmen who don't know what they are doing.

Le_Kirk

Where was the water going when you were topping up? Presumably if the pressure monitoring device (gauge) was showing low pressure when it wasn't and you were topping, up the pressure must have been building up in the system.

Eccles01

Well of course I don't know where the water was going (not being a technician) but in order to install the new pressure sensor I know that my gas man emptied the boiler itself of water although not the rest of the system. Having refilled the boiler, he then brought the whole system back up to 1.2 BAR and it has stayed that way ever since. Incidentally, I may be wrong but I believe that these modern systems have a way of relieving themselves of excess pressure (water) if necessary.

bouicca21

I have had a similar problem with loss of pressure. Initially every few months then more or less instantly. Plumber said it was a leak under the floor so I contacted insurance company who have been amazingly helpful, organised thermal imaging which identified two leaks - one slow and one massive.

Insurance will not cover the actual repairs to the pipe work but cover consequential damage which given the nature of my floors is going to be well into 4 figures.

Le_Kirk

Eccles01 wrote: »

Well of course I don't know where the water was going (not being a technician) but in order to install the new pressure sensor I know that my gas man emptied the boiler itself of water although not the rest of the system. Having refilled the boiler, he then brought the whole system back up to 1.2 BAR and it has stayed that way ever since. Incidentally, I may be wrong but I believe that these modern systems have a way of relieving themselves of excess pressure (water) if necessary.

You are correct in that there is a relief valve. I had assumed (wrongly as it turns out) that this had been checked during the initial diagnosis. Normally done by finding the pipe that should go outside and tying a plastic bag over it to capture water. Anyway, glad you are all OK again now.

Before anyone else says it I know that to assume is to make an a s s of u + me!!

Eccles01

Actually, it mystifies me why some of these guys don't seem to work with a comprehensive list of possible faults starting with the simplest. Before retiring, I often worked with complex computer based business systems and always worked with such a list starting with "Has the power failed or been switched off,LOL? Yes, you may laugh but you would not believe the number of times that was the answer in my career.....