Worcester Bosch 28i Junior Boiler Pressure Drops

Hi

I have a 1 month old Worcester Bosch 28i Junior boiler with which I have the following problems:
1) The pressure falls from 3 bars to red in about 5 days. I've had someone around to check the boiler, they had a look around and could not find any leaks on the rads. He said that there must be a leak in the piping which is under the concrete, although I have not seen any wet patches on the concrete. He said he may be able to put some chemicals in the system to seal the leaks. Is this wise, could it damage the boiler? Could there be a problem with the boiler itself and no leaks underground?

2) If I keep the boiler on continuously I've noticed that sometimes (even when the pressure level is still on green), and every morning), it stops heating the rads despite me changing the thermometer room temperature,and thermometer clicking doesnt restart it. So I have to click the continuously on button upwards on the boiler itself, although it's already on 'On' position, for it to restart heating the rads. Any ideas what the problem is? The strange thing is that it seems to work ok during the day with the roomstat, only when I check it in the mornings after it's been running for about 24hours does this occur.

I personnally dont like or use leak sealers they are only a temporary solution. Was your system powered flushed when the new boiler installed? I always do and therefore I warn customers about the very slight chance of getting leaks in existing pipe work and/or rads due to the cleaning process (I always print a disclaimer on my quotation saying if this happens it is extra charge to correct).

It certainly sounds like a leak somewhere in your floor then. Try pressurising the boiler, shut the ch isolating valves and see if the pressure still drops (although you can't use the heating) or get someone in to air test your pipe work.

The person who came round to check, was it Manufacturers or installer?

Hi

Thanks for the reply. The system was powerflushed. The person who came around is the installer.

How is the pipework airtested, and I dont really understand what you mean my shutting the ch isolating valves and pressurising the boiler (can I do this or would the installer do this?). I do increase the pressure in the boiler every few days. Somebody mentioned they had a similar problem and said that there is some sort of air pump in the boiler which may need to be filled up with air.. that's what fixed their problem..does that make any sense?

The air test in the pipes and the pressure test, can the installer do this or would it have to be the manufacturer?

Also, I don't know if it's related but when I run the hot water in the bathroom tap, it turns cold after a few minutes then hot again then cold etc. I rang up worcester and they said this is normal, although this never happened in a valiant boiler I had before.

Best regards

sunni said:

Hi
How is the pipework airtested, and I dont really understand what you mean my shutting the ch isolating valves and pressurising the boiler (can I do this or would the installer do this?). I do increase the pressure in the boiler every few days. Somebody mentioned they had a similar problem and said that there is some sort of air pump in the boiler which may need to be filled up with air.. that's what fixed their problem..does that make any sense?

The air test in the pipes and the pressure test, can the installer do this or would it have to be the manufacturer?

Also, I don't know if it's related but when I run the hot water in the bathroom tap, it turns cold after a few minutes then hot again then cold etc. I rang up worcester and they said this is normal, although this never happened in a valiant boiler I had before.

Best regards

Click to expand...

Firstly in answer to the last point I think Worcester are filling you with a load of b*******! You are supposed to be able to run as much hot water as you like.

Have you checked whether you are losing any water out of the safety discharge pipe outside, especially when it is running hot and cold on the hot tap? This may gush or drip constantly.

I think the best answer here is to call your installer and get him to place a service call to Worcester if only for your last point! Have you told him about this fault?

I can only think that the 'air pump' your friend refers to is the expansion vessel that is charged to approx 1 bar. Again worcester will check this for you or your installer.

The ch isolating valvs should be under the boiler between the 22mm copper pipes (flow & return) and the boiler. Turning these off after pressurising the system will leave the boiler sitting there with the pressure having no where to go. To air test your system you would need to connect a compreessor to a 't' or the like, shut ch isolating valves, pump up to about 1.5/2bar and leave for about 60mins. If you get a pressure drop then you definatley have a keak in your pipe work somewhere. This does not need a CORGI as you are not interfering with any gas or boiler connections.

Why did you change to Worcester and not stay with Vaillant?

Hi
Thanks for the explanation. Im away from home this week, I'll check the discharge pipe when Im back next week, and switch the CH isolating valves off, and monitor the pressure for a day or two and see if it still drops. If I switch these valves off and leave the roomstat on and the boiler running continuously, how would the heat move away from the boiler, it wouldn't overheat would it? Anyway I'll ask the installer to run these tests just to be safe, and to arrange a worcester service call. Will report back then.

I had a Vaillant in my old flat, just moved to this place recently and I had old conventional non corgi system replaced with the worcester combi, I should have stayed with Vaillant boilers.
Cheers,
sunni

NOTE previously I said that you would not be able to use the boiler with the isolating valves off

sunni said:

Hi

I have a 1 month old Worcester Bosch 28i Junior boiler

Click to expand...

Not that I want to open up a can of worms but why has your installer fitted a non condensing boiler? I can understand if he has achieved a dispensation on the points system but these are very few and far between.

Stan

Hi
I believe it is a condensing combi boiler

If it is a condensing boiler it will be the Greenstar Junior 28i. 'Plain' Junior 28i is non-condensing Has it got a plasitc drain (overflow pipe size) connected to it under the boiler?

Hi

There is a white plastic overflow pipe under the boiler, I thing it connects to the waste pipe

/BR