Heating help (again!) - rads on when heating not on (tropical!)

[unbelievablejeffrey]

Hoping that someone can advise me - had heating issues before, but this is weird! Last Friday night, I put the heating on +1 hour around 9PM to take the chill off. DP came in around 11PM and I realised the heating was still on (rads warm), but the hour had long gone and the light on the timer panel was not on. Odd. I had it on auto as the heating was set to come on the next morning, but I just turned it to manual off and thought I'd worry about that the next day (& as it was a weekend it didn't matter so much, wasn't going to be an early morning rise). Went to bed and thought nothing of it (well, a little bit!) - woke up at 5AM very warm - the thing has been off now for over 6 hours and the rads are all one (hot water fine, we have a combi). Rang British Gas - advised to turn off boiler (pain in backside in the loft), did so and rads went off. Engineer came round that afternoon, 2 hours of testing, no problem, good boiler and must have been a blip. Surely if it's on manual off, nothing should happen? Fine. Oh and the noise it makes that you can hear outside (!) periodically is the water keeping itself hot for instant use - perfectly normal. So this morning, I didn't have the heating on auto as it is milder out (& DP is not working today and he is the one that needs it warm in the bathroom in the morning - I'm tougher!) - but no, it's on full blast. But it's on MANUAL OFF. No light on. We did have it on manual auto yesterday and it worked as usual...I am off to work now and DP is sleepily blissfully unaware. It's quite frustrating as I had to cancel my plans on Saturday to call them out and I know the engineer investigated and said without seeing it there wasn't much he could do (but British Gas advised that I turn the boiler off and on when on the phone, and it was so hot!), but this is silly - can anyone shed any light? I have to go to work now - I am going to leave it as is - not going to clart about in the loft (ladder and dust!) I really hate unexplained things. Oh and to add, hot water is fine this morn. We had baths and showers last night (with no heating on).

[lastnightiwenttomanderley]

Did the person from BG check how h our control panel was wired? Could be a simple back to front wiring so having the hot water set to on is actually controlling the heating (and therefore the hot water too?

[AdorableMisfit]

We've had this problem before, but we have an ancient boiler and water tank. Whenever we put the hot water on, radiators came on too. The plumber who came to look at it said there's a valve thing which is meant to be closed when the radiators are off, but this was stuck in the open position. It didn't take long to fix.

[unbelievablejeffrey]

So I don’t know what he did lastnightiwenttomanderley – well he looked at the panel in the kitchen (didn’t take it off) – he had the boiler front off though – this is indeed in the loft sootica – I didn’t watch him the whole time, he was up and down though and asked me to turn the heating and hot water on and off several times, and he said it was all fine. I have had the boiler for nearly a decade and no issues though, so can it suddenly be wired wrong (I would have thought not!)? I did have a new bathroom installed in August 2014 with new towel warmer and then a little later I had a thermostat put in (which I have always felt was not quite right), but this issue only happened on Friday PM and then again this morning, so it sure has taken a while to develop if it is wiring! The frost thing is interesting, but this weekend was quite mild (don’t I know it in the tropics!) and when there was the recent cold snap, no such thing happened… AdorableMisfit, the hot water is available on tap (boom boom!) as it is a combi boiler – the heating does not come on when you put the water on, so it’s not that issue (and I definitely was not running any water in the early hours of this morning!). I guess I am going to have to get them back in, but what a pain…this sort of thing makes me live on my nerves a bit – it’s odd – the engineer looked a bit like he didn’t believe me! I am not a techy at all, but I do know that MANUAL OFF means it should be Dickensian temperatures should I wish it to be. And that noise…he said it was the ‘warmstart’ system. But it never used to make that noise and on combi boilers the water is supposed to be instant and hot…I wish it wasn’t all computers and wires – a crank handle would suit me!

[Ruhrpott]

We had this. Was also the valve stuck in the open position. The plumber came and squirted it with wd40 shifted/whacked/ moved something with a screwdriver and left. It's been fine ever since though he did say it's old and needs changing sometime or it will probably jam again.

It was this one on the right

Pigletjohn knows more about these things and the technical terms for them all.

[Ruhrpott]

It was the square box valve thing not the red round heating pump

[PigletJohn]

you say it's a combi, so there is no hot water cylinder, is that right?

[unbelievablejeffrey]

Thanks for the visual Ruhrpott – perhaps I can show that to the BG engineer!

Yes PigletJohn, it’s a combi – I know you know how terrible I am at these things, but I do know that! No idea about a hot water cylinder though…Valiant Ecotec if that is any help?

DP obviously not up yet (or in a heat induced coma!) – I really don’t want to have to be going up into the loft all the time….

[unbelievablejeffrey]

DP has just phoned (he didn't actually notice the heating was on!), but when I asked he did say yes it was - he has gone up in the loft and switched the boiler off and then back on again at the mains.

[PigletJohn]

if there is no cylinder, then I expect it is the diverter valve, which is inside the boiler casing and needs a heating engineer. It is the combi equivalent of the 3-port valve on systems which have a cylinder.

If you boiler has a "keep hot" facility, turn it back to the "Eco" setting, which will prevent the hot water from firing up intermittently.

To test this, turn off the heating at the timer or wall stat, let the radiators go cold, then run a hot bath. Do the radiators start to warm up, probably beginning with the ones nearest the boiler?

[unbelievablejeffrey]

Thanks PigletJohn - I have booked an engineer to come on Thursday PM (though I wont be there, DP will have to supervise!) - I explained the problem to the BG person and they seemed to know what I was saying which is good! I think I am going to get them to turn it to Eco...I am just worried that will mean the water will not be hot when I want it? I did take a screen shot on Saturday of the engineers explanation of the warmstart system function (attached) - he said I could do it myself, or I could call them back...I wonder if when I had the stat fitted this was turned on by the installer? I am going to print this off and leave with DP - I know they know what they are doing, but there is a lot of computer business and not a lot of elbow grease (perhaps wont show them that part of the thread!)

[PigletJohn]

Turning it to Eco is only a temporary bodge. The diverter needs changing.

[unbelievablejeffrey]

Thanks! I'll be leaving a note for DP to make sure this is investigated - I was all proud of my boiler passing inspection and then this...I don't suppose he should have left without sorting the problem, but I just don't think he knew!

[unbelievablejeffrey]

Hello - thought I would give an update. BG engineer (same one) came round on Thursday (I was at work, DP supervising). I wrote up everything and also put down the possible causes to investigate from here. Again the engineer said there were no issues - he was here a while. He put in a new kitchen panel (a Drayton one instead of our old Siemens one - Drayton is the same as our stat). DP said he was on top of it and set the hearing for Friday morning...but it didn't come on! When I looked, it's because he had it on off! It was quite mild yesterday anyway so no drama. We then both got in after 11 last night and DP put the heating on to take the chill off - all lovely. Woke up this morning - heating on 'off' - bathroom rad/towel warmer was slightly warm. Hall was hot as was the kitchen one. The bedroom ones and living room appeared off. There are two pipes next to the spare bedroom one and one is hot (the central heating supply?) Anyway, I guess that's fine if those rooms are less than the 20 degrees the stat is set to? I'm a little surprised though the spare room which is unused (& usually chilly) wasn't less than the 20 degrees through...bathroom one cooler now - I put the floor heating on about half an hour ago and it is saying the air temp is 23.5...so confused...happy if this is how it is supposed to work, but not convinced!

[unbelievablejeffrey]

Underfloor heating (for bathroom) and timer panel in kitchen just now.

[Spanglecrab]

Which boiler do you have?

[unbelievablejeffrey]

Hi Spanglecrab - it's a Valiant Ecotec

[Spanglecrab]

There are two versions of this boiler. This advice assumes that you have the slightly older model with two thermostat knobs towards the left hand side.

The bottom one controls the hot water temperature. Turn it all the way down (anti clockwise) then after five seconds set it back at its usual position.

This will turn off the hot water preheat.

If this resolves the problem then let your engineer know that the diverted valve needs changing.

Piglet john already suggested this might be the problem. Please update and let us know.

[unbelievablejeffrey]

Thanks Spanglecrab - it's about 10 years old but it is a good one I think...in my note I left for the BG engineer, I said to check the diverter in the first instance as PigletJohn suggested. He's coming back on Thursday to see how we are getting on, again it will be DP supervising - slightly frustrating as the engineer has heard the noise when he was here but told DP to record it. And he was a bit dubious about the heat coming on when the panel was off...why would I make that up? Can you imagine if we went on holiday for a week and it just came on? Sigh.