Combination (of) boiler faults

[ChrisR]

Ideal Response 120

WHen I'm there it's just fine, can't make it go wrong - nowhere near overheating and lights every time.
Tenants report that sometimes it squirts steam from the aav, and cuts out on overheat , needs reset button pressing.
But when I arrived it was locked out on Ignition lockout - reset by power on-off.

I can't think of anything to cause both problems (apart from it being a Response)

Pain in the bum this one. It's had a bunch of everyday Response faults fixed in the last few months.
Ideas (other than skippy)?

 

[Agile]

It should have had the recall modification!

Perhaps it was fittted by a non registered person and the warranty never registered?

 

[BDL]

Intermittent dhw flowswitch sticking.

Bet if you take it out and stick a u guage tube into the pipe you will find a small black o ring or a piece of debris.

 

[gas4you]

I agree if its steamin and banging when taps on. New heat exchanger if not like all responses every 5 years

 

[corgiman]

I agree with the DHW flow switch but not with the heat exchanger, Had loads of em leak but never seen one block up yet, even if it would fart and die while you are there chris wouldnt you say!

what about a sticky pump?

I dont really know bin the bloody awful thing and tell watchdog to have a word with ideal and give potterton a break

 

[gas4you]

I've had 2 block up and heard of others.

 

[corgiman]

they must be terrible systems to block up a 15 mm 28mm concentric heat exchanger!!!

still first time for every thing

 

[gas4you]

Lanlords flats obviously put in on the cheap incorrectly

 

[corgiman]

would love to see one

 

[gas4you]

If ever I get another one I will take a photo cut open. Highly unlikely though as I do not go out to response faults anymore. Just tell customer to get Ideal out. Let them sort out their own mess

 

[ChrisR]

Thanks for the sticky flow switch suggestion - wouldn't have expected that on one of these.

Couple of weeks ago I had the f.s. out cos I thought it should have been switching on when it wasn't. Then compared with a new one and found it much the same. They need a lot of flow to switch them on, about 3 litres/minute. This boiler only HAD about 3l/min, so I descaled the HW side, (and removed restrictor) which got the flow up to 9 l/min. Hooray I thought.

On quizzing the tenants, they say that although they noticed the flow a lot better, the sporadic overheating hasn't altered. Rules out the sensor side though really. I mean it would have been much worse on 3 l/min...

I know, I'll take the fs out then turn the mains back on. Full. Blame the tenants for the mess - at least it should clear the beggar out.

If it woz a sticky pump (not used on HW) then it should do it sometimes on CH. More tenant quizzing required.
Yes it should have had the "recall" stat fitted, but then it would really be a pain (By the way you CAN reset them despite what they say)

Also, if it was a stuck FS, and it boiled and went off, and the tenant reset it - it would just boil again. It doesn't, afaik.

Landlord (company) wants the boiler "kept going" because they want to do a major refurb in the summer. If they put a new boiler in now, it would simply get stolen.

 

[Agile]

On quizzing the tenants, they say that although they noticed the flow a lot better, the sporadic overheating hasn't altered. Rules out the sensor side though really. I mean it would have been much worse on 3 l/min...
:

Not necessarily!

The flow switch is a reed relay operated by a magnet.

If you loosen the grub screw you can slide the reed carrier about and even get in a position where the SW is on all the time!

Its still quite possible that the reed is not releasing!

The test would be to leave the outer case off and point out the DHW demand light and get the tenants to see if its on when overheating. Thats if you could trust them!

At this time of night I cannot think of anything else. But I am happy that I solved a difficult causal problem this afternoon that took me two days of thinking to resolve.

Tony

 

[ChrisR]

Ah, by

Rules out the sensor side though really. I mean it would have been much worse on 3 l/min...
:
Not necessarily!

I meant the temperature sensing side, sorry.


Yes I've moved the reed about on those - you can get them to be more or less sensitive to flow. MAybe I should DEsensitise this one so it needs 5 l/min!
I've also instructed one of the tenants to remove the cover and look for red ights! Last time I was there I left a pretty picture...

 

[Agile]

The hysterisis on the reed is designed to be quite high to ensure they give positive switching without fluttering.

It may need to be set to rather higher than 3 li/min. I have always had 3.5 li/min in mind.

I have encountered situations where it had to be carefully set to avoid staying on after a demand has ceased.

Tony

 

[ChrisR]

Thanks - sounding likely then. Just noticed it sayeth on the switch
On max 4.5 l/min
Off min 3.25 l/min
makes a change to actually find a spec. But then it's German.