Halstead Ace High not modulating burner on DHW

[richardmlees]

I have a Halstead Ace HIgh boiler which is providing intermittent hot water. When a a hot tap is open, the water gets very hot, then the boiler cuts out, then fires up again. Leaving the tap open for a while causes kettling, and the overheat to trip. The problem seems to be that the gas burner isn't being modulated on the DHW, but the CH side seems fine.

Any ideas what this could be? The corgi man is thinking the PCB, but I'm loathe to change that at £150 - £250 if it turns out to be something else.

Any suggestions would be greatly appreciated.

Thanks

 

[bengasman]

Sounds like crap in the system to me; very common, especially on cheap boilers.

 

[richardmlees]

Thanks Bengasman. I've currently got some Fernox running in the CH side of things. Is this likely to help the DHW side, or do I need to do something else to clear the hot water side?

 

[PEDANTICVINDICTIVEMAN]

If it has a DHW plated exchanger, I would take it off and clean it out with drain cleaner.

PCB my arse.

 

[ChrisR]

The corgi man is thinking the PCB

He's probably a dork, then.. (Most of us are )
CHeck the HW thermistor ( see manual) but most likely it's dirt in the ch side of the tap water heat exchanger. this boiler needs it very clean. Clean it, Halstead prices are silly.
Do a search on "DHWHE", "secondary heat exchanger"

 

[richardmlees]

Thanks PEDANTICVINDICTIVEMAN. I've currently got the boiler running on a 'spare' DHW exchanger. I've tried caustic soda on the original DHW H/E but it still doesn't look properly clean. The spare (fitted by Corgi man) is supposed to have been cleaned up prior to being swapped in. Since the heating side seems to be OK, I'm wondering whether there is something I can do to effectively flush the DHW side of things?

 

[ChrisR]

As I said, the side which is a problem is the boiler side, NOT the tap water side. That's most unlikely to collect any scale.

Caustic soda is a waste of time, it doesn't dissolve scale at all. You need acid, like hydrochloric or phosphoric or citric, but not sulphuric.

If the guy changed the hex without checking the sensor, yes he's a dork.

 

[richardmlees]

Thanks for all the help everyone. The acids Chris mentions, am I likely to be able to get those at my local Plumb Centre?

In terms of the sensor, Corgi man did check that, and swapped out just to be sure. Problem is that the 'replacement' is from a boiler he has taken out from elsewhere and is keeping for spares (courtesy of Halstead prices). I'll try and get some acid tomorrow and check the sensor myself.

I'll let everyone know how I get on.

Again, thanks everyone.

 

[dneill12345]

the best thing to use is FX 2 liquid i use it all the time to descale plates and it leaves them as good as new.pour it in and leave it for 20 mins.you will know when it is done because it will stop fizzing. you can pick it up from plumb center and i have seen it in some independant merchants too.

 

[Agile]

Any ideas what this could be? The corgi man is thinking the PCB, but I'm loathe to change that at £150 - £250 if it turns out to be something else.

Any suggestions would be greatly appreciated.

Thanks

Its not very clean what you have engaged the Corgo for!

If its to fix your boiler then thats what he should be doing.

He should not charge for parts that are not needed.

Its most unlikely to be the PCB.

A simple thermal survey in the boiler should highlight whats wrong.

Tony

 

[richardmlees]

Hi Tony.

Yes, Corgi man is supposed to be fixing the boiler. He's had his multi meter out, tried swapping a sensor, and swapped the dhw hex. Both the sensor and the hex are from a scrap boiler he's keeping for spares. Neither of these has made any difference so he suggested flushing and is thinking if that doesn't work that it will be the PCB. The hex he's fitted was apparent;y cleaned up prior to swapping it in.

Because the pcb is expensive, and the spares he's fitted are from a scrap boiler, I'm just trying to double check before the board gets replaced, though he's current;y trying to 'borrow one' from somebody so we can try.

To be honest, the problem with my hot water has now being going on for a few weeks and I'm getting a bit fed up with it so thought I'd start looking into it while the flush is running.

Thanks.

 

[bengasman]

Just out of interest, you keep calling him the corgi man, but are you aware of the fact that corgi has not had anything to do with gas safety for two years now?
Corgi still exist as a commercial company, and you can become a member and be "corgi registered". However, it has no legal meaning and appears to depend more on your willingness to pay them money than anything else. You most certainly can become "corgi registered" without having any certificate, diploma, qualification or experience working with gas.
Did you verify that the chap who dealt with is actually a bona fide registered installer with GSR?

 

[richardmlees]

???? Hang on, I thought Corgi was registered/trained to work with gas? What's GSR? I've been referring to him as 'Corgi Man' just so I can refer to him without divulging who he is. The main reason I called anyone out at all is that, while being reasonably handy, I don't play with gas and thought Corgi registered would be OK?

OK, I'm not convinced about the PCB being the issue (but may yet be proved wrong) but other than that, everything he's done seems logical, though I'm curious what he cleaned the (currently temporary) hex with before fitting (my hunch is tap water).

The reason I started looking into this is because I wasn't convinced the PCB was the problem, and I object to the Halstead prices for something with so few electronic components. Having seen this, I've now got a few other alarm bells ringing (like his comments about 'where is the air coming from' because the boiler is kettling - I would have thought it fairly obvious if the boiler isn't modulating on the DHW side?)

Again, what's this GSR bit, and what should I be looking for in terms of boiler repair-men and gas fitters?

 

[bengasman]

???? Hang on, I thought Corgi was registered/trained to work with gas?

Indeed, WAS is the operative word.

What's GSR?

CORGI got booted two years ago and are succeeded by Gas Safe Register, or GSR for short.

Just google Gas Safe Register and go to " find installer".
Type in his post code, and look at the people listed; you should even find his picture there so you can verify that he is not working under somebody else's registration.

 

[richardmlees]

As it happens, he is GSR registered, and to be fair, he seems to know what he's doing; at least in the main. I only started this post because I've recently been made redundant and am therefore loath to spend Halstead prices for a board.

The thing that now REALLY bugs me is that if any small business (plumbers and gas fitters included) so much as farts in the wrong direction, a big deal is made of it; yet I don't recall much of an issue being made over the switch from Corgi to GSR?