Leak on pressurised heating system!!!

[ct8282]

Hi peeps. I'm new here and have stumbled across this forum in a desperate effort to try and resolve the ongoing nightmare of my leaking heating system.

Cutting a 7 year story as short as possible then....

I came home from work about 6.5 years ago to find my boiler making a hell of a noise. When I opened the cupboard door in a panic I soon realised that the pressure of the system was '0' and the boiler was trying to run but couldn't circulate anything. I managed to find the refill loop and topped the system up. Things carried on as normal for a couple of weeks until the problem occurred again. I realised there was a leak so I called out a plumber who filled the system with 2 bottles of leak sealant. This seemed to fix the problem so I forgot about it and got on with my life.

Summer came and the heating system was not being used as to be expected. Then winter came and it was time for the boiler to start getting it's usual daily pounding. Within a couple of weeks I noticed the pressure had almost completely dropped again and it has been a battle of topping up the system periodically ever since. Sometimes the pressure will drop only 0.5 bar in the space of2 or 3 weeks. Sometimes it will drop almost to 0 in the space of 1 or 2 days. It varies and there doesn't appear to be any consistency at all.

I called in a plumber and a consultant chap to investigate and they spent nearly a whole day isolating all of the legs from the manifold, and used a device which pressurises the leg and then you wait to see if a pressure drop is observed. None of the legs showed up a pressure drop and the consultant chappy started saying that I might have a leak inside the boiler itself. However, they investigated the prv and drainage pipe and couldn't find any problems there either. Based on the characteristics of the pressure increase when the heating comes on (0.5 bar increase) they concluded that the expansion vessel is not to blame either. I have always been convinced that the leak is in the pipe work somewhere as my immediate neighbour had similar issues and they eventually found a poor joint behind the wall of their bedroom radiator.

So, all this work but the problem remains! However, I have now sold the flat and the new occupants are due to move in to the property in a few weeks and I am desperate to get this resolved before we exchange as I couldn't bare the thought of them inheriting this problem. They are first time buyers and are young and don't have much money. I want to do the right thing but also need to get moved out asap as my partner is expecting our first baby in a few months and we are trying to purchase a house.

So, tonight I have spent hours trawling the web and have found this forum which has had some interesting info. I also called a specialist leak detection company who gave me advice over the phone. They said that based on the inconsistent characteristics of the pressure drop this would certainly imply that the leak is inside the boiler. They told me to pressurize the system, close of the flow and return pipes to the boiler (using the quarter turn screw) and then watch to see if the pressure still drops. They said that if it does this proves that the leak is inside the boiler.

I have done this and the pressure dropped about 0.2 bar in around 90 mins. Does this mean that I have at least identified that the leak is indeed inside the boiler???

Any expert advice would be greatly appreciated as this has been plaguing me for so many years now. :sad3:

 

[ct8282]

Anyone?

 

[dhgas]

Make & model of boiler?

 

[ct8282]

Ideal ICOS HE24

 

[stevetheplumber]

if it loses with the system isolated then yes its boiker

 

[ct8282]

if it loses with the system isolated then yes its boiker

Ok, thank you. So any ideas on the cause. I've read that it's unlikely to be the expansion vessel as the pressure increases normally when the heating comes on. Could it be the plate heat exchanger or something else?
Any ideas on how easily it can be fixed and hoe much this might cost?

 

[dhgas]

If there are no signs of an external leak, then the only explanation left is an internal leak to the heat exchanger with the leaked water being removed through the condensate trap.
Before you jump in though, 0.2 bar drop could also be due to a drop in temperature between readings. Make sure that it does keep dropping.

 

[ct8282]

If there are no signs of an external leak, then the only explanation left is an internal leak to the heat exchanger with the leaked water being removed through the condensate trap.
Before you jump in though, 0.2 bar drop could also be due to a drop in temperature between readings. Make sure that it does keep dropping.

Thank you very much indeed. I will wait for the temps outside to increase a little so I can do the same test and leave the boiler off throughout the day.

Sorry to ask another question but how difficult and costly will it be to have the heat exchanger checked/repaired/replaced?

 

[jtsplumbing]

If you are going down that route you may want to replace boiler some of these heat exchangers can be expensive never done one on a icos but could be £400.00 +.

 

[ct8282]

If you are going down that route you may want to replace boiler some of these heat exchangers can be expensive never done one on a icos but could be £400.00 +.

Surely replacing the boiler would several thousand...?

 

[Gray0689]

Lol no a boiler not anywhere near that price
If you give your location there may be a member on here near you to give you a price

 

[jtsplumbing]

No, heat exchanger / labour arround £600.00 You could fit a new 24Kw boiler for around £1200.00 as a stright swap shop around for price some good deals on at the moment.

 

[ct8282]

Thank you. I just figured a new boiler would be like £3k or more.

If I had some form of insurance would this type of thing be covered under the policy? Would they look to fix the issue or would they replace the boiler under an insurance policy?

 

[Gray0689]

No your house insurance won't cover this as it would be under wear and tear I'm afraid

 

[peteheat]

Did anyone check the safety valve? It may have a weak spring causing water to escape outside.

 

[Mike Jackson]

If you confirm it's the boiler at fault the cheapest option is an Ideal fixed price repair.

 

[jtsplumbing]

I agree with Mike Jackson ref the fixed price repair ! but most will not cover Main Heat Exchanger, their`s also a couple of other parts they will not cover, ask if you call what is coverd ! :mickey:

 

[WHPES]

Before you go down that route, shove a bottle of leak sealer in. It's only about £6 from Toolstation and sometimes does the trick, so worth a try.

 

[jtsplumbing]

Be careful with leak sealer some boiler Manufacturers DO-NOT advise it !! :ban:

 

[ct8282]

Update on this. I have since spoken with a plumber and he does not believe it is a leak inside the boiler as there are no visible signs of water coming out of the prv/overflow pipe outside, and there is no sign of water dripping out the bottom of the boiler and never has been. He is convinced the leak is on the pipework somewhere.

So, I have done some more investigating and today I took away the foam covers from the pipework around the cylinder. Running my fingers around the bit nuts and screw threads there is very clearly water leaking at these joins!

I have shown these areas with the read rings. At the top red ring there is a brass tap (no idea what it does) and this feels wet, and the pipe coming down from this tap is wet.
The blue rings show very obvious corrosion to the pipes.

The question then, would these leaks cause the pressure drop that I have been experiencing for several years now?