Halstead Quattro intermittent hot water

howiehilton · 29 Jan 2008

Hi.
I have a problem with my Halstead quattro combination boiler.
If I call for hot water, the boiler fires up every time. The water will usually run warmish then cold. Sometimes it will run warm and then get hot, and will be OK for a day and the next time will run cold. When the DHW temperature is altered on the front of the boiler, I can hear the burners increasing.
Looking at similar problems on this site, could it be sludge in the DHW heat exchanger? Looks tricky to get to on this boiler. I also thought it may be the DHW thermistor, but maybe not if the burner increases with a turn on the temperature dial? What do you reckon?
Last year I replaced a diverter valve (with your supurb help

) so thought Id check with you guys first.

Thankyou

dreaddan · 29 Jan 2008

I've got the same boiler, I've had the diafram replaced every year since having it to cure the same problem

howiehilton · 29 Jan 2008

thanks for the reply. hmmm... i just didnt think it would be the same problem with the diaphragm. I seem to remember the boiler wouldnt fire up last time - after turning on a tap, it was 50/50 whether it would fire up. This time, it fires every time. Do you think it could still be the diaphragm though? I guess theres only 1 way to find out.
thanks

howiehilton · 4 Feb 2008

I've had a look at the diphragm in the diverter valve. All seems fine in that area. I'm stuck now - does anyone have any ideas?
thanks for your help Howie

howiehilton · 5 Feb 2008

Ive just swapped DHW and CH thermisters - no difference. Is the problem the heat exchanger? - I could check it out but it looks impossible for a DIYer to get it out. I really do need a shower soon. help

Trundles Tricks · 5 Feb 2008

Blocked DHW heat exchanger.

Wouldn't have thought a DIY job, new heat exchanger £115 or theres a place up North ( forget exactly where, I've got the brochure in the house somewhere) where I've had two from now £29 + £15 delivery.

howiehilton · 5 Feb 2008

thanks mate. I have the manual and it looks like its easy to remove (4 steps) but getting it out of the boiler seems a badger as the gas control valve looks like its in the way. If I had someone in, would they be able to flush it out still connected?

Trundles Tricks · 6 Feb 2008

Wouldn't have thought so.

I have to apologise I didn't read your post properly and just assumed that you were on about a Halstead ace high, I've never had to work on a quattro.

If the innards are similar to the Aces then it does wangle out quite easily after being unbolted.

Sorry if I've misled you by not paying attention.

howiehilton · 9 Feb 2008

right - I have taken off the DHW heat exchanger and cleaned it out/descaled it fairly throughally. After putting it back the problem remains (plus a couple of small leaks

) It didnt seem like there was too much sludge or scale in it so I dont know if that was the problem. Before taking it off however I was sure it was because a little tap on it and we had hot water (for a bit).

Can anyone suggest something else to try?
If not a plumber in warwickshire (Napton)?

thanks for your help... much appreciated

howiehilton · 9 Feb 2008

help. anyone?

howiehilton · 14 Feb 2008

I dont mean to keep on answering my own posts but just in case anyone may be able to help, do you think it could be a PCB problem?
There is one going on ebay for £5 at the moment and if there is a slim chance it could be I may buy it.

thanks for your help

Agile · 14 Feb 2008

howiehilton said:
Can anyone suggest something else to try?
If not a plumber in warwickshire (Napton)?

thanks for your help... much appreciated

I had another nice meal in the Castle Balti last night!

Good food and good sized portions. Nice way to relax after a few boiler repairs!

Tony

howiehilton · 14 Feb 2008

I went recently as well. I'm ashamed to say the naan bread totally beat me. Awesome food though I agree.

I could pay you in Castle Balti vouchers Tony!

ChrisR · 14 Feb 2008

Check your diverter is diverting. WHen the heating's off. turn a hot tap full on and leave it on. Go grope your FLOW pipe (fattie under the boiler). If it's warm hot then your DV is "letting by", so some of the kW are going to heat your radiators instead of HW.
First time you do it it'll take a while, to remove the DV, strip it down and lube and replace it. There are kits of bits - one for an ariston will do for example. Ask in a parts emporium.

I tried to fit a "pattern" DV to one of these and had to strip the original instead, the other (Banico) wouldn quite fit

howiehilton · 14 Feb 2008

Chris R. Thankyou very much for the info! will check that out.

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Halstead Quattro intermittent hot water

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