Water loss from C/H system

[dicksable]

An ideal Mexico floor standing (replacement) boiler was put in in Sept08. It was fine for about 3 months and then the header tank kept emptying out. It is an open vented tank which I fill manually.

The system will lose about 2-3 gallons of water per day. It was suggested the heating coil in the H/W tank was perforated and water was being lost that way. I replaced the tank and there are no leaks anywhere.

The condensate pipe drips when the boiler is firing, but does not when it is not firing. A couple of gallons of water disappear on a daily basis and there is no sign of a leak anywhere in the house. (The boiler is in the house and a leak would be obvious) I'm baffled - the water in the header tank does not get hot so it is not evaporating.

One thing I note which is a little odd - the boiler fires when it is heating up and often turns off for quite a while. The pump is running and the water passing through the boiler can become cold for a couple of minutes before it begins to fire again. I would have thought it would fire all the time the boiler temperature thermostat indicated the water was below the set temperature.

Is there any way the heat exchanger could crack without water being seen around the boiler?

 

[mickyg]

its possible the heat exchanger is leaking into the condense. If you can leave the boiler off for say 24hours and check what comes out the condense pipe.

 

[bengasman]

... It is an open vented tank which I fill manually...

Why is that?

 

[mickyg]

... It is an open vented tank which I fill manually...

Why is that?

boredom

 

[bengasman]

... It is an open vented tank which I fill manually...

Why is that?

boredom

Sounds like that problem is properly solved now.

 

[dicksable]

By filling it manually, I monitor the system, If a valve is fitted, as is normally the case the valve can stick 'up' as it is not used much.

I'll try monitoring the water from the condenser.
Thanks

 

[bengasman]

Did you install it yourself? I don't install ideal's but from what I remember, the M.I. don't allow the setup you have.

 

[dicksable]

I have removed the sump plate from the heat exchanger and viewed the condenser collector. No water is falling from the heat exchanger at any point I can see, no water drips from the condenser waste pipe when the boiler is not firing. The header tank will still lose about 4 gallons over 24-48 hours when the heating and hot water are in use.
Thanks for the help which is being given.

 

[bengasman]

That clearly means your boiler is not working properly and is not safe to use either; you need to get a pro out to check it all.

 

[dicksable]

Another point - the boiler is a replacement for an ideal Mexico which had been in service for about 25 years, and was fitted into exiting system which only needed to be modified to accept the different pipe fittings of the newer boiler.

 

[bengasman]

Was that done by a RGI?

 

[dicksable]

The CORGI fitter who replaced the boiler was the same person who advised that the leak could have been caused by a pinhole in the heating coil of the indirect tank. I was doubtful at the time because the CH tank water level is at a lower level than that in the HW tank, so a leak should have caused the level in the CH tank to rise or overflow, but it doesn't. The water from the CH header tank just disappears.

As I have had to meet the cost of replacing a perfectly well working (but inefficient boiler) and the cost of a replacement hot water tank, I am anxious to see if anyone else might have some idea of why the water disappears.

 

[bengasman]

Water loss = leak, it's that simple.
You still have to get a RGI out to make sure the boiler is installed and operating safely.

 

[Biggles..]

the boiler was installed by an RGI why get another to see if its installed correctly when the op has a water leak not a gas leak.

water=plumber

have you got any pipes under a timber floor downstairs,embedded in screed or hidden in a cavity or other unobvious place.

if your loosing that much you'd notice it otherwise.

you could add leak sealer but thats a cheat not a proper fix.

 

[bengasman]

the boiler was installed by an RGI why get another to see if its installed correctly ...

Because he has had the combustion chamber open, and I find an installer swapping a boiler without at least assuring there is an automatic topup in place, is rather suspect.