Discuss Hot water but no Central Heating with young children in the Central Heating Forum area at PlumbersForums.net

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We have a Potterton Titanium Combi Gas Boiler which was setup with the wireless Nest Thermostat last year to provide heat to our radiators, heat up our unvented indirect cylinder to provide us hot water and to heat up our under floor heating in our kitchen.
There is also one tap in the house that is used to provide hot water directly from the gas boiler instead of the cylinder - Something to do with making sure the 'diverter valve' does not fail and has regular use.

The nest thermostat setup has worked flawlessly for just over a year and tonight when I wanted to heat up my sons loft room, the rads would not get hot.
I firstly checked the nest thermostat and it mentioned it had an issue connecting to the link. I tried to reconnect and it connected straight away (this happens from time to time due to the distance of the thermostat and link).

I then went to check the boiler and it was not heating up although powered on.
I checked the single tap that heats up using the boiler directly and this worked instantly.
Going back to the nest, I then attempted to heat the cylinder up, which again worked - boiler was in operation, same applies for the kitchen.

I then tried to set the thermostat to high temperature (23 degrees) and whilst the nest goes orange and says it is heating up, nothing happens at the boilers end.
At closer inspection and playing with the thermostat from getting the boiler to heat up and off, I can clearly hear click at the links end when it is calling for heat yet no impact on the boiler.

What could be the issue and how can I resolve it please?
I have 3 young children and the loft bedroom currently is at 15degrees and dropping!

Attaching a pic of the boiler in hope it explains the setup better
 

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Hi Take a look at the two units on the left, two port valves, turn hw / ch on in turn... they should wurrrr - i suspect one doesn't- the one for the heating, there's a little lever that you can gently push over and hook- the heating will then work- but you need an heating repair person to confirm and repair. ATB
 
Just attempted to change as suggested and called for heat, with no change.
 

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Just attempted to change as suggested and called for heat, with no change.
Turn the power off, then only turn heating on, listen for the gentle wurrr, if not move the lever over and feel the pipe, it should warm up. You will need and engineer if this doesn't work.
 
As said above. If you can identify which zone valve is for your radiator circuit manually move the lever over and it should hold open. Then bring on HW cylinder circuit through programmer. I can't and wont advise if it's a problem with the boiler as I'm not qualified to but it sounds though it's an electrical fault before the boiler.
 
looking at the whatsapp image somebody had a load of sockets they needed to use up on the condensate p/work. in the pic you have 2 valves locked open of the three, cant see what the other is doing. you say hw and underfloor is working. if you know which of the 3 valves is the loft leave it locked open but you will only get heat into the loft when either the hw or underfloor puts a demand on the boiler. if both hw and underfloor are upto temp and switched off get somebody to have a bath which will use up hot water firing the boiler again. this will give you limited heating to the loft while cylinder reheats. in the end you need a gsr/g3 engineer to attend
 
Exactly what I was getting at Garygvl. Of course the OP will only get loft heat if theres another demand and yes it will be short lived unless things were linked out (obviously I will NOT say what). If I was to have a guess it's the synchronous motor that's burnt out, motor wont turn over and wont connect end switch. The OP needs an engineer from here on out.
 
Thank you for all your responses.
It turned out to be a faulty zone valve (far right).

I have managed to put it in manual override mode and when getting the underfloor heating to come on or/and heating up the cylinder, the rads now heat up as well.

I assume this will not be covered by the warranty of the boiler.

Is the zone valve an easy fix to replace?
How time consuming can it be and roughly how much should parts and labour cost?
 
It's just the head of the zone valve or maybe even just the synchronous motor inside that needs replacing. Highly unlikely to be covered under warranty. It's an easy fix for an engineer yes, so you'll have to call one out.
 
Thanks for all of your help.
I managed to purchase a HONEYWELL 40003916-001 2-PORT V4043H REPLACEMENT POWERHEAD 22MM 22MM COMPRESSION from screwfix and watched a youtube video of how to change the motor from the old zone valve.
Was very straight forward and although it was difficult getting a thin enough screwdriver to get the case/motor off.
All working again now.

Thank you all!
 
So it was the synchronous motor like I said?
[automerge]1575758990[/automerge]
That's good. You'll find a lot of so called engineers would just of changed the head, any one worth his weight in gold would of isolated the problem and just changed the motor, cheaper for the customer and a sign they know their stuff. Glad you got it sorted
[automerge]1575758992[/automerge]
That's good. You'll find a lot of so called engineers would just of changed the head, any one worth his weight in gold would of isolated the problem and just changed the motor, cheaper for the customer and a sign they know their stuff. Glad you got it sorted
 
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So it was the synchronous motor like I said?
[automerge]1575758990[/automerge]
That's good. You'll find a lot of so called engineers would just of changed the head, any one worth his weight in gold would of isolated the problem and just changed the motor, cheaper for the customer and a sign they know their stuff. Glad you got it sorted
[automerge]1575758992[/automerge]
That's good. You'll find a lot of so called engineers would just of changed the head, any one worth his weight in gold would of isolated the problem and just changed the motor, cheaper for the customer and a sign they know their stuff. Glad you got it sorted
Yes agreed but I have cjhanges the motor and then had to go back to change the head so..... 50/50 it doesn't always worktrying to save the customer money, and difficult to justify a second charge.
 
I agree Ted it's not justifiable to charge for the same problem twice but with careful testing most culprits can be identified on first visit. In this case the spindle was free to move through manual lever, so we know that was ok and he said he was getting feed from stat so instantly I was thinking motor burnt out, not motoring over and not contacting end switch. This being a Honeywell valve the manual lever wont contact the end switch, it can be done if you take the head case off and use a peg, other two ports do contact the end switch if you manually move lever I believe. Either way it's fixed now 🙂
 
Glad you got it fixed.

On the other hand, and as a general comment, I think we panic far too much these days about cold houses and I suspect there's actually a level of misinformation driving a trend of ever-warmer houses because, otherwise, as houses become more energy efficient, the oil/gas/coal companies won't make enough profit. I actually think that the authorities are themselves being lobbied by people with a vested interest, or that 'comfort temperatures' are driven as much by current practice as by what is actually safe. So now we seem to consider a house under-heated unless you can walk around comfortably in a swimming costume.

So long as you have thick covers and a hot water bottle, my personal belief is that heated bedrooms in houses are entirely unnecessary, except perhaps for people with particular medical conditions (though, I accept that once, in a caravan, when it was well below freezing outside, I actually needed a heater on (on the lowest possible setting).

Within an occupied house, it would be unusual for temperatures to drop below 10°C, which will usually be quite enough. I used to get ice on my bedroom windows as a child and, in the 80s, it was officially (council housing standards) quite acceptable to have a kitchen or hallway at 13°C. I think this did a lot for household cohesion as nobody would hide away in their bedrooms during the day and people invariably spent sedentary time in the warmer rooms.
 

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