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Upstairs UFH not really working


ChristyJH

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Hi there

 

I have a similar problem to the other “zone not warming up” on here. 
 

I purchased a new build house with an ASHP in the summer this year so now is the first time it’s really been asked to heat when temps are consistently below 4 or 5 c for a period of time. 
 

Downstairs is fine but I can’t seem to get upstairs above 17/18c (despite stats set to 21) and it then drops gradually throughout the night (with stats still on 21). 
 

There is a manifold upstairs and downstairs. I’ve tweaked the flow rates on all the upstairs ones, sometimes turning off all downstairs ones and some upstairs (ie. to try and heat just one or two of the rooms) but no joy. 
 

I was under the view that because there was flow rate that there wasn’t an air lock or blockage? Is that right? The house stood complete for about a year before we moved in so could air have got in the system?

 

I thought the builder might have put in too thick carpets however I’m not sure that’s the case as some of hard floors upstairs (bathrooms) aren’t really warm and carpets in areas down stairs are fine. Also, in some of the rooms upstairs with carpets you do feel occasional hot spots (ie nice and warm) but then step three feet to the side and it’s not warm. Also, if you later go back to that hot spot it is no longer warm. 
 

Any thoughts welcome. Thanks in advance. 
 

Chris

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There is usually a thermometer on the manifolds to show the flow and possibly the return temperatures.  Can you post a picture of your upstairs manifold while the UFH is on please?

 

Carpets will slow down the rate of heat into a room.  What times of day is the heating on?  It could be as simple as needing the heating on for longer?

 

Can upstairs and downstairs be set at different times?

 

What is the level of loft insulation like? it would not be the first time a mass market builder has not fitted enough.

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Hi there. Thanks for response. 
 

Manifold is in teenage daughters bedroom so can’t access at the moment! However, pic of downstairs one attached and no temp gauge on. 
 

I seem to recall feeling the flow and return pipes and they were similar temp which was a little concerning(??) but would need to double check this point. 
 

stats have been set to 21 for days and never got to that temp. Downstairs reached temp and then switches off. 
 

insulation is fine I think. Double layer at least 12inches thick in loft. 

EA879368-EA81-45E2-8C8C-CB0913934753.jpeg

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You only have manual bleed points on the left of that manifold.

 

If the other manifold is the same (and is the highest point in the system?) Then it will accumulate any air. You can try periodically opening the bleed screw to let out any air.

 

Long term it would be an improvement to fit an automatic bleed / vent on the manifold and the highest point in the system if there is anything placed higher?

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Thanks. I think the upstairs manifold is the highest point. Do I bleed the valve on the flow or return? Or both? I think I’ve tried that before but a thin jet of water came out so I closed it. Do you need to keep it open for longer and collect the water some how?

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So no blending valve and no manifold pump?  Time was I only ever saw UFH done "properly" with all the kit, but there is an increasing number of "basic" systems popping up on here.

 

When you next have access to the upstairs manifold, try as above bleeding air from the bleed valves, and then check that all the flow meters (the things on the top manifold) are registering flow.

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1 hour ago, ChristyJH said:

I seem to recall feeling the flow and return pipes and they were similar temp which was a little concerning(??)

I think you’re unlikely to feel the difference by hand. 

 

2 hours ago, ChristyJH said:

hard floors upstairs (bathrooms) aren’t really warm

I don’t think they should feel warm, if they are warm then it’s probably too hot. I can only describe mine as not cold. Which keeps the house at a level 21-22 degrees. 

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There is a manifold pump upstairs and down stairs. Pic of downstairs attached. I think the blending goes on over at the ASHP/ tank set up in my garage. I can see that the the flow of water for heating is c50c and separate flow for HW at c.48c. 
 

I still waiting for access to the bedroom to try and bleed. 
 

before this there was always flow on each loop and I tried increasing and decreasing them (ranging from 0.5 to about 5 l per min) but no joy with heating temperature. 
 

question. Can you still have an airlock / aide in the system AND get flow? The hot spots in certain parts of the floor are confusing me. 
 

thanks. 

2CC4BD47-619E-44AD-8BC6-6F0A624753C2.jpeg

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48 degrees sounds very warm for UFH.

 

How many heating loops upstairs?  It is possible there are 2 runs of pipe for the larger rooms and perhaps one is flowing and one is airlocked so only half the room is being heated which would explain hot and cold spots.

 

Time to get the teenager out of bed?

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Gav. Thanks. On your points. 
 

when I put my hand on flow and return downstairs there is a much more noticeable difference than upstairs. 
 

on the floor temp I would say they are definitely cold. I appreciate they won’t necessarily get warm but when compare to exactly the same floor downstairs they do feel colder (hence why not getting above about 18c upstairs )

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Single pump can’t really run two manifolds like that - one will always be starved of heat as the closest and shortest loops take the flow. 
 

That pump is on full - try rotating all the way anticlockwise to get the pump running on proportional flow. 

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Do you have any form of thermometer, e.g a handheld IR thermometer to get a measure on flow and return temperatures?

 

Are you SURE all the loops showing no flow are really off and not just flowing?  If the rooms are all below their target temperature, I would have expected them all to be on.  There are a lot of loops there so almost certainly 2 per room.

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I turned stats off on the ones with no flow but turned on. All at between 1 and 3. There are nine loops and only 1 per room. 4 x bed. 3 x bathroom 1 x dressing room 1 x landing.

 

I don’t have and IR thermometer unfortunately. Flow and return feel similar temps to the touch. 
 

ive opened both the bleed valves and a thin jet of water comes out on both. Do I need to leave open for longer and collect water?

 

pic of current flow rates attached. 

4165209C-A40F-408A-BA5E-19E812BFFC5D.jpeg

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So you have flow to all loops now.  Temperature is probably reasonable if it feels warm.  All you can do is wait and see, perhaps run the upstairs UFH for longer if possible?

 

If water comes out of the bleed valves you have no air so that is okay.

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Does the downstairs manifold have its own pump ..??

 

I wonder if the ASHP pump is pushing water through the downstairs manifold and back to the ASHP and bypassing upstairs. 
 

Are there any zone valves ..??

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