Why are two upstairs rooms not getting heated? :(

scarletjim

Does anyone here know anything about underfloor heating? It's in the house I bought 2 years ago, and the last couple of weeks I've noticed that my bedroom and en suite are both not getting any heat, irrespective of what level I put the thermostat on (individual thermostats for each room).

I'm not sure if they've had heat this winter, maybe not and I just only noticed recently due to the weather change, but they definitely worked fine last year. So yesterday I did a bit of internet research, learned a tiny bit about timers, manifolds and actuators (but not much), and had a look in the cupboard. As far as I can tell:

1. The timer is fine - it goes off and on when it should.
2. The system generally is working, as the other bedrooms are being heated.
3. The flow pipes to the cold rooms are cold. Internet says the red indicator on the top should tell whether or not water is flowing, but none of these seem to indicate anything, they are all cloudy, and some of them have the red indicator at the top (i.e. off) even though they clearly have hot water running through them and are working perfectly, so that doesn't help, and I can't see how I'd be able to adjust them even if I did know what I was doing, they are just glass tubes, there is no 'adjuster'.

Here are 3 pictures in case my descriptions are not sufficient:

https://dumpyourphoto.com/album/gXR1jfGc8J

I've removed the white thing (actuator I believe) on one of the offending pipes, but still no heat, well no obvious water flow. Is it just about 'balancing', or am I likely to have some kind of blockage stopping water getting round that part of the system?

Anyone know what to do? I'm happy to get an engineer if needed, but don't want someone to turn up, press or twist something in 2 mins, then charge me £150.

Thanks in advance for any help anyone can provide.

I_have_spoken

Blimey, with a system that complex, I'd be booking onto a Nu-Heat training course! http://www.nu-heat.co.uk/s.nl/sc.7/category.17629/.f

Just a guess but I'd be thinking the actuators are stuck after being unused for a while and aren't moving when getting a signal. YOu could try waiting until they should be 'open' and gently tap around the actuator body with the handle of a large screwdriver.

scarletjim

Haha at £99+VAT, doing the course would actually probably end up cheaper than getting an engineer in to look at it! Though unfortunately, I'm not very good at such things, so I suspect I would be lost within 30mins and spend the entire day just annoying everyone else with my lack of understanding!

Back to business - I actually removed the actuator (the entire white thing) from one of the offending pipes, and there was still no flow - I read somewhere that doing that should give it unrestricted flow - so I assume it must be a blockage somewhere.

If no one on here can offer much advice, looks like I'll have to get an engineer - so I suppose next question is, do I need a 'Nu Heat' one as recommended in the original paperwork (minimum £135+VAT), or can I just call any old underfloor heating servicing company? ... ???

marlot

Do the radiators have TRVs (thermostatic valves)? TRVs can often be a bit sticky at the start of the season - I would regularly have to take the heads off mine and tap the needles a few times.

scarletjim

I don't have radiators - it's all underfloor heating.

espresso

scarletjim wrote: »

I've removed the white thing (actuator I believe) on one of the offending pipes, but still no heat, well no obvious water flow. Is it just about 'balancing', or am I likely to have some kind of blockage stopping water getting round that part of the system?

Anyone know what to do?

When you removed the actuator head, did the pin move freely when pressed?

scarletjim

Do you mean the inside of the actuator, or the pin on the top of the pipe when I take the actuator off?

The metal pin on the pipe is solid, doesn't move, and that's the same for all of them, even the ones that work. However when I look inside the actuators (I took two off to compare), there is a plastic bit inside, and on one actuator it's raised, and in the other one it's flush (see pic below). What does that mean? How do these things even work?

https://dumpyourphoto.com/album/photo/Y1jiuVVGP1

I_have_spoken

Have you tried swapping the actuator head from a circuit that is heating-up to the circuit that remains cold?

NB The pin should move, the suppliers recommend freeing it with a flat screwdriver - http://www.nu-heat.co.uk/s.nl/ctype.KB/it.I/id.17582/KB.122/.f. If they're like TRV valves it won't budge just pushing it with a finger, you need to push hard with the side of a large screwdriver.

scarletjim

That is sooo helpful, many thanks, I'd struggled to find the right help bit on a website. Earlier I removed the actuator altogether from the pipe for my bedroom, and left the system for a couple of hours, and I now have a hot bedroom - so it does seem to be the actuator (for that pipe at least) where there's a problem. Will see if removing it and replacing it has 'freed it up' so that it will work overnight, or if I'll wake up to a cold bedroom again tomorrow morning...

At the same time, I'll do same test with the en suite...

Would be a bit of coincidence if they had both 'gone' at same time - but perhaps they didn't, perhaps they gave up some time during the autumn several weeks apart, and I just never noticed, it was very mild after all...

I will 'report back' in a couple more days if you don't mind taking a look, as the above it most helpful, thanks.


EDIT: A couple of questions though if you have a moment:
1. When you say the pin should move, I assume you mean up and down, not side to side (it does neither yet...)
2. What does this white actuator thing actually do? Is the knob part just to make it easier to get on and off, or does moving it say half a turn one way or other actually alter anything?

espresso

scarletjim wrote: »

That is sooo helpful, many thanks, I'd struggled to find the right help bit on a website. Earlier I removed the actuator altogether from the pipe for my bedroom, and left the system for a couple of hours, and I now have a hot bedroom - so it does seem to be the actuator (for that pipe at least) where there's a problem. Will see if removing it and replacing it has 'freed it up' so that it will work overnight, or if I'll wake up to a cold bedroom again tomorrow morning...

At the same time, I'll do same test with the en suite...

Would be a bit of coincidence if they had both 'gone' at same time - but perhaps they didn't, perhaps they gave up some time during the autumn several weeks apart, and I just never noticed, it was very mild after all...

I will 'report back' in a couple more days if you don't mind taking a look, as the above it most helpful, thanks.


EDIT: A couple of questions though if you have a moment:
1. When you say the pin should move, I assume you mean up and down, not side to side (it does neither yet...)
2. What does this white actuator thing actually do? Is the knob part just to make it easier to get on and off, or does moving it say half a turn one way or other actually alter anything?

Yes the pin should move up and down freely but it doesn't move far and should spring out when pushed down and released. It is common for radiator TRV to stick when they have not moved for some time and your actuators are very similar.

The removable head is a motorised actuator that presses or releases the valve pin, controlled by the thermostat for that zone/room.

There is an indicator showing if it is open or not - left closed, right open.



The heads should all be fitted in the same position as your original photos, turning them left or right does nothing.

scarletjim

Well, this is the second consecutive morning where I'm waking up to a comfortable temperature, so the fiddling around at the weekend obviously worked. Thanks so much for your help, I would have ended up paying £150+ unnecessarily without it. This is why MSE is so great sometimes - not just the concept, but the willingness of individual people to help others. Merry Christmas!