Hastead Noise

Hi folks, hope someone can help me out

I have a Halstead Hero75 boiler, almost out of guarantee. Since buying I had to have a new heat exchanger about 9 months ago, apparently there was a design fault in the original that was leading to loud banging noises which I was continually complaining about, and three new boards to stop the banging caused by a delay in ignition when the system was calling for more heat but there was a delay after the initial "click" as the gas started coming through. Not impressed with all this especially as the ignition bangs appear to have started again, heard a couple last week.

We had the heating system re-piped 18 months ago by another firm, as previously we had a leak underground-concrete-which gave rise to all sorts of problems, now plastic microbore. When I went to bleed the rads at the start of autumn there was not a scrap of air in the system to come out.

In the airing cupboard there is a valve that controls the flow of water, ie CH only, HW only or both together.

Current problem is that for 5/10 minutes or so at the end of the first heating run, and during the subsequent short runs until the system stops calling for heat, there is a new noise, a bit like rushing hot water or kettling (so the engineer says). This does not happen however when the boiler is supplying both the CH and the HW, or HW on its own. This seems strange to me (who knows nothing) as surely the heat must be getting up the same high temperature prior to the boiler shutting down, whatever the demand is. I had the boiler serviced a couple of weeks ago and it's my impression that the problem has started straight after this, though I could be wrong and had merely not noticed before as little use made of the heating side up to then. The problem igets worse the high the boiler tepm. is set, though I normally have the knob about halfway between - and +.

No bypass valve, I was told I didn't need this in view of the valve thingy in the airing cupboard.

I am getting very frustrated by the whole thing and have even got a quote for a new boiler, as after the engineers last visit I felt like having the dam thing ripped out and starting again!

Any ideas would be very welcome, as whilst I don't feel like spending money on what could be an ongoing basis and chucking good money after bad, now that I've calmed down I don't really want to start all over again with a new new one.

Help please, Arni

I wander of they are having problems with the spark generator? Get it analysed and a new one fitted for the explosive ignition, get a spare one for the next time.

Don't know about the rest.

Just hope for your sake it's not part of the main board.

No bypass valve, I was told I didn't need this in view of the valve thingy in the airing cupboard.

Click to expand...

Wrong.
The valve will probably stay in the CH only position, after a CH run. If you have thermostatic rad valves fitted, then there could be nowhere for the water to go.
After HW or HW + CH, it can still go round the cylinder.
If you have mostly TRV's and only one normally valved rad, which is permanently left open , on microbore, it'll be a restricted route.

It could be that with new microbore the flow isn't enough to get the heat out of the boiler so it gets a bit too hot. Check your pump, to see if it's a 5metre head or a 6m one. (15-50 is 5m, 15-60 is 6m). Check it's on highest speed.

Can be scale in the boiler contributing too - which would be annoying after less than 2 years, but can happen much faster than that

Explosive ignition can be several things - make sure that's attended to before the gtee runs out.

Hi Chris

Thanks for that, lots to think about. The pump is a 15-50, is that ok or should it be the 15-60. I forgot to mention in the earlier post that I have 9 rads and a towel rail. The valve thingy is a Drayton Mid Position Actuator MA1, does this sound ok

Thanks for the help, Arni

see blue edit - didn't quite make sense.

If your boiler is kettling you have some sort of scale issue so a system cleaning product(s) would be worth a try - eg "Boiler Descaler", and/or Fernox DS-40.
It may be bunging up the pump which is presumably only the 2 years old?
If changing the pump I'd use a 6m version - you can always turn them down.

Thanks Chris

The pump is two or three years old but runs very quietly and is on max. Chap is coming Monday for another look. May well suggest the cleaner you mention if no other positive ideas come forth. It was suggested it might be a circulation problem caused by the microbore, but we had this last winter and no problems were evident. I drew off a jar of water and popped a couple of bright nails in, in the hope it might assist in the search.

The chap I got a new quote from reckons Halstead are not much cop and that I shall be paying out regularly with it, but then.........he has got a vested interest in supplying a new one.