No Hot Water

KentishLady

Hi we have an Alpha CB24 Gas Boiler.

Over the weekend we began to have intermittent problems with the hot water and we can now only get hot water if the central heating is on and the boiler is already lit for the central hearing IYSWIM.

If I turn the CH off, so the boiler is set to Hot Water only then no matter how many hot taps I turn on, and no matter whether they are fully open or partly open the boiler does not light and no hot water is produced.

If I turn the CH on, and the boiler kicks in to heat the CH water I can then get hot water if I turn the taps on when the boiler is already lit. If the boiler is not already lit and I turn the taps on it does not kick in.

We have one of those homecare agreements with BG and the man came today to look at the boiler. As I work FT and DH does not work he was here and let the man in. I did speak to him on the phone. He said he was trying to recreate the fault but they had had the taps running and they were producing hot water - he had not been able to reproduce the fault. He had turned the CH back on and mentioned that there appeared to be sludge in the system because the radiators were not heating up in the middle and bottom - only at the top.

As he couldnt recreate the fault he said it must be intermittent and the only thing he could think of was that some sludge or dirt was getting into the system and stopping the boiler from kicking in. He has recomended we get the system flushed out.

I don't have a problem getting the system flushed because to be honest I did know it was going to need doing at some point.

However, I can't see how dirt or sludge can get from the CH system over to the hot water part of the boiler. I assume that there is a hot water senser(sp?) which tells the boiler to kick in when a tap is opened and that this is isolated from the CH part of the system?

My concern is that once the system is flushed we will have a CH system which works perfectly well, but we still won't have any hot water unless the CH is turned on.

Can anyone give me any pointers as to what DH should be saying to the heating man tomorrow when he comes to flush the system?

thanks
KL.

Forgot to say that before the hot water packed up completely, we had warm-hot water if we ran a hot tap but the minute a cold tap was turned on (or the loo was flushed) the boiler would cut out. A bit of a problem if you are running a mixer shower.

Canucklehead

Hi

The problem sounds like the diverter. This may or may not be due to system sludge/dirt. (the diverter has contact with the c/h water so can be affected)
Have you personally felt the radiators to see if they are cool at the bottom middle? after the system has been running for a while.
Are you paying for the flush? and how did you know the system might need a flush at some point?
Re; your edit.
Flow switch not detecting flow?

Corgi Guy.

KentishLady

Canucklehead wrote: »

Hi

The problem sounds like the diverter. This may or may not be due to system sludge/dirt. (the diverter has contact with the c/h water so can be affected)
Have you personally felt the radiators to see if they are cool at the bottom middle? Yes - bathroom radiator cold at bottom and middle toasty at top, kitchen rad barely working at all, similarly radiators upstairs cold at bottom/middle. after the system has been running for a while.
Are you paying for the flush? Yes we are paying for the flush - insurance doesnt cover it. and how did you know the system might need a flush at some point? Had a previous problem where muck from system had got back into the boiler stopped it working (think it got stuck in a valve or switch).

Re; your edit.
Flow switch not detecting flow?

Corgi Guy.

I've now dug out my manual for the boiler so will leave this our for the BG man tomorrow. Maybe then he will work through the trouble shooting guide in there properly (rather than turning on the CH and saying you've got hotwater!!).

Trouble is, DH is disabled (and has mental health problems) so he's not very good at explaining to people what is wrong with a boiler!!!!!!!

I suppose I'm going to have to take the morning off to be here when the BG comes aren't I.

KL.

Canucklehead

Hi

Sounds like a lot of gunk in the system.
A flush when the boiler was changed and a Boiler Buddy or Magnaclean would have avoided the problems .
The skill level of the BG engineers varies quite a lot. In theory you shouldn't have to explain the problem in great detail, in reality...... a morning of work is probably best.

Good luck

Corgi Guy.