Ariston switching on

[Iain]

Hi

I have an Ariston microGenus 23 MFFI. While I was using no hot water nor central heating, the boiler was on and stayed on for over 10 minutes (after I first saw it). The lights showed the water temperature was going up and hot water was coming through the hot water outlet (not the heating). Shortly after it went off, it went on again briefly. The temperature showed the water was cooling, and the hot water outlet pipe went cold.

(It is on the Economy setting (not Comfort). The heating temperature is on maximum and the hot water is just below maximum.)

A couple of minutes after that, the boiler went on again briefly (hot water getting quite hot), then it went off. It then went on and off three more times, all within a period of a minute. Once it went on and off so quickly, the boiler didn't have time to ignite.

I have noticed in the past that the boiler quite frequently seems to switch on as though it is being used. I video-ed the above two episodes. It all seems to work fine with me (hot water and heating).

What is the likely cause of this?

Thanks, Iain

[David Hansen]

On Tue, 15 May 2007 15:16:43 +0100 someone who may be "Iain" wrote this:-

Assuming it is a combination boiler, probably it has a reservoir of domestic hot water and it is firing to keep this warm.

[Martin Pentreath]

Very odd. David's suggestion about the reservoir of hot water is ruled out by the boiler being set to "economy" (the alternative "comfort" setting on the Microgenus tells it to keep the little reservior hot). Even if the comfort/economy selector is broken it wouldn't come on very much at all or stay on for very long on the comfort setting, certainly not for ten minutes.

I'm not really sure that I understand your post fully, but you say that while the burners were burning for ten minutes the domestic hot water outlet (ie the pipe to the hot taps) was hot and the radiators were not on? The only causes for that are:

1) someone opening a hot tap somewhere; 2) a leak (a very fast one that you would notice!) somewhere in your hot-water pipework; 3) a circulation loop, where a pump keeps all the water in the hot- water pipes hot all the time to speed hot-water draw off from the taps; or 4) a poltergeist taking control of the system.

priest than a heating engineer.

Cheers!

Martin

[Iain]

I was trying not to make any leading statements and see what the feeling was ...

The plumbing originally served two flats. My landlord replaced the boiler with the current one and said he had disconnected the system (heating and hot water) from the other flat. I am now solely responsible for the bill.

I agree with your comment about the 'Comfort' setting, especially that it should not last for over 10 minutes anyway. The noises coming from the boiler when it is working, and I am not using it, are the same as when I use the hot water taps, ie. the 'clicking' as the boiler turns itself on and off. I am not sure whether the comfort settings make that noise or not when activated.

I certainly believe that there is another hot water tap, not in my flat, connected to the system and being used. I am more atuned to the boiler working when I go into the kitchen and I am not using anything. My landlord's reply to my recent email about it was, "We have a gas certificate for your flat. It may be possible that the temperature has dropped and the thermostatic value automatically comes on to re heat."

Apart from physically going into the other flats (there are three here and occupied) and checking them, is that any way that I can provide conclusive proof that there appears to be a 'rogue' tap attached to the system? Would the 10+ minute long video be good enough - I walk over to my taps and washing machine at the end to prove that they are not on? I have another couple of videos, but not nearly as long as the 10+ minute one.

Thanks, Iain

[philbertio]

Turn off the boiler and see which of your neighbours complains about no hot water? It's going to be hard for your landlord to fix their hot water if it's coming from your system!

[EricP]

Turn the DHW off for 24 hours and, if you can, turn the water supply to the boiler off. This will flush out the owner of the illicit tap on your system. From the use you list, the monitary loss is very small but you must get it sorted on principle. :))

[Iain]

I've tried turning off the boiler. If I am away for the weekend I sometimes turn it off. There don't seem to be any complaints of a lack of hot water. So I'm not sure what the situation is there. It could be that they are aware it's not their hot water, or the already-hot water goes through their own heater / boiler. I have no idea where the feed stop-c*ck is, but I'll have a look for it. But I don't want to do any damage to the system.

Thanks for all your comments / observations, Iain

[Martin Pentreath]

arrangement where the cold feed pipe enters the boiler, in other words there's a screw that you just need to turn through 90 degrees to cut off the supply. That's more likely to flush them out than just turning the boiler off and leaving the water running. I can't see that it could damage the system. If you try to use the boiler when there's no water it just won't come on.

If it was me, and if the above tactic fails, I'd probably spend hours with the floorboards up tracing the pipework, freezing it where it tees off to nextdoor, and putting a valve in there, but I'm not normal.

To be honest I'm slightly disappointed to hear that it's not a poltergeist. Demonic possession of domestic hot-water systems would help to explain many symptoms observed by their users.

Cheers!

Martin

[Martin Pentreath]

PS What a lot of old bollocks! The landlord clearly knows that you're picking up the bill for someone elses hot water. Are you sure you've not been heating their rads all winter too?

Cheers!

Martin