Halstead Ace High Kettling

[willrobs]

High

I am working on a Halstead Ace High combi. It has developed a problem whereby after it is suplied a good amount of DHW (ie fill a bath), a minute or two later it kettles (boiling sound and foam from auto air vent).

Can someone explain the mechanism by which this boiler should prevent this happening? presumably there is a pump that sould be staying on to prevent the water in the boiler from overheating - what triggers this? Is it a stat or timer on CPU? Just want to be a bit more accurate before I start replacing bits!

Cheers

Will

 

[Kip]

Is the boiler taking a little while to cut out after the flow of hot water has stopped?

 

[willrobs]

No it cuts out right away and is completely silent. Then about a minute later the boiling noise starts.

Will

 

[Kip]

Hmmm, the fan should over-run to take the excess ammount of heat away to prevent kettling, so best be to check the that the fan is over-running, as when the hot water stops flowing what your doing is actually allowing the hot water to sit there and just heat up. So like i say, check your fans over run as i beleive that is the only method the boiler will use to prevent it kettling. I beleive.

 

[willrobs]

Thanks Kip
I don't think the fan is overrunning - I will check it tommorow. What triggers the fan to overun? Is this done via a timer on the PCB or is it done via a stat if so which one?

Will

 

[andy b]

Hi Kip
did you cure the problem?
i have the same with my Halstead,i took a gamble and replaced the plate heat exchanger but it is still overheating
thanks
Andy

sorry not Kip but Willrobs!!

 

[Mbear]

Will people never learn, if your boiler is kettling then change the pumphead.

Fan overun!!? Give me piece

 

[Billy Bob Bob]

Will people never learn, if your boiler is kettling then change the pumphead.

Fan overun!!? Give me piece

agree wtf is a fan over run? its a pump or muck in the diverter i have seen the bases block before

 

[oldplumber]

thought i had missed out on some essential piece of learning, never heard of a fan overrun previously, i must try it some time though with a customer as it sounds quite impressive, especially as fans cost more than pumps lol

 

[willrobs]

Hi all

The problem was that there was debris inside. Ironically there was gunk (a lot!!!) in the filling loop and everytime the pressure dropped after kettling many times and needed topping up I was introducing more debris. Boiler flushing solved problem - filling loop cleaned and removed and whole CH system flushed, cleaned with some sentinel stuff for 3 weeks, flushed again and inhibitor added. No Kettling anymore. The BG man who came to look and flushed the boiler quoted 650 for powerflush and magnetic cleaning thingy but I did a mains flush and didn't install a filter (yet) now I know problem I'm waiting to see if it comes back but it's been quite a while now (couple of months) so think it's sorted.

Will