UFH not heating upstairs

MrsQuestions

I have underfloor heating both upstairs and down with a Baxi gas boiler. Downstairs is working fine but upstairs does not seem to get to temperature. I have all the stats upstairs set to high temperature from 6 to 8 am and from 5 to 10 pm. Any ideas would be very welcome.

Has it ever worked? may need bleeding. is the manifold getting warm? is it on a seperate pumped circuit? are the actuators opening?

Are the rooms warm enough??? some people have installed upstairs UFH and found that heat rising from downstairs was sufficient and the system never came on!

I'm sure there are other questions but there's enough to be getting started with. good luck

MrsQuestions

It does seem to be working. The actuators are opening. The temperature in the manifold does seem to be rising but very slowely and extremely slowely if downstairs is on.

At the moment I have down stairs on at the same times as downstairs. I was wondering if I should have downstairs on all day and maybe that would heat upstairs. But the concrete floors seem to stop the heat from rising.

@30deg

UFH in concrete floors in very slow to respond, I leave ours on 24/7 (water temperature @30deg C)and the actuators switch in randomly as needed.

Sounds like downstairs is getting "first refusal" of the hot water and as you have the heating on for relativly short periods, downstairs actuators may never shut.

smashey

Moved to DIY.

yop

What temperature is on the gauge on the mainfold upstairs? check that the feed/flow pipe to the mainfold is warm to the touch, also check the returns from the loops back into the mainfold, they should be very very luke warm, but not cold.

Is there an expansion tank near your boiler with a pressure gauge on it? Should be in or about 2 bar of pressure.

You may have air in the system upstairs, it may not be setup correctly, the water may not be getting upstairs.

How long has it been in, how long has it been playing up?

MrsQuestions

Manifold upstairs do seem to be getting hot water but it hits 40 degrees and then drops to 30 straight away.

System was install 3 years ago but has never worked very well upstairs.

MrsQuestions

The loop backs are warm.
Presure guage is 1.75

MrsQuestions

Deleted User wrote: »

UFH in concrete floors in very slow to respond, I leave ours on 24/7 (water temperature @30deg C)and the actuators switch in randomly as needed.

Sounds like downstairs is getting "first refusal" of the hot water and as you have the heating on for relativly short periods, downstairs actuators may never shut.

What temperature do you have the stats in the rooms set to? Do you have all rooms with UFH (including bedrooms)? Are all rooms set to a high temperature all day every day?

I did not want to increase the amount of time the heating was on for as it is using a lot of gas as it is.

MrsQuestions

MrsQuestions wrote: »

What temperature do you have the stats in the rooms set to? Do you have all rooms with UFH (including bedrooms)? Are all rooms set to a high temperature all day every day?

I did not want to increase the amount of time the heating was on for as it is using a lot of gas as it is.

I have most of the rooms set to 18-19 deg C all day and the house has a very steady temperature.

BTW it's a bungalow, but yop has a two storey house.


As you can see the internal temperature of the house is very stable, it takes a lot of energy to raise the iinternal temperature in the first place but much less to maintain that temperature (assuming a well insulated house with MHRV).

MrsQuestions

MrsQuestions wrote: »

Manifold upstairs do seem to be getting hot water but it hits 40 degrees and then drops to 30 straight away.

System was install 3 years ago but has never worked very well upstairs.

Does the manifold have an integral pump, if so then these blend the hot water coming in with the cool water in the UFH pipes thus stopping very hot water entering the system and possibly cracking the screed.

macapaca

Deleted User wrote: »

I have most of the rooms set to 18-19 deg C all day and the house has a very steady temperature.

BTW it's a bungalow, but yop has a two storey house.


As you can see the internal temperature of the house is very stable, it takes a lot of energy to raise the iinternal temperature in the first place but much less to maintain that temperature (assuming a well insulated house with MHRV).

Dolanbaker... what are you using to record & keep track of the temps?

macapaca

macapaca wrote: »

Dolanbaker... what are you using to record & keep track of the temps?

A weather station, with internal & external sensors. see the website in my sig.

ennisjim

Not sure if this helps, but I just had my UFH turned on for the first time this week. The heating expert who commissioned it spent some time setting the flow rates for each circuit. Is there any possibility that your problem is related to flow rates ?

MrsQuestions

I did wonder about the flow rates. Who did your install? My installers are no longer in business.

Also, did he recommend how long the heating should be on each day. I was told to have it on from 6 to 8 am and 5-10 pm at 21 degrees in kitchen and sitting rooms. 20 in bedrooms.

ennisjim

ennisjim wrote: »

Not sure if this helps, but I just had my UFH turned on for the first time this week. The heating expert who commissioned it spent some time setting the flow rates for each circuit. Is there any possibility that your problem is related to flow rates ?

Setting flow rates is critical if you are controlling the system from only one stat but less important if using one stat per zone, but in the OP case the rooms are (if I understand correctly) never getting up to temperature - slowing down the flow through the downstairs system would help.
I think that if the system was left to run for longer the problem would eventually go away as the whole house will eventually reach the desired temperature.

One other question: does the boiler run for the whole time during the "ON" times, in other words do the downstairs zones reach the desired temperature before the end of the timed heating.

MrsQuestions

Deleted User wrote: »

One other question: does the boiler run for the whole time during the "ON" times, in other words do the downstairs zones reach the desired temperature before the end of the timed heating.

The downstairs rooms do react temperature, the boiler kicks in when one of the rooms drops in temperature.

MrsQuestions

MrsQuestions wrote: »

The downstairs rooms do react temperature, the boiler kicks in when one of the rooms drops in temperature.

If that's the case then there should be pleanty of hot water for the upstairs system, assuming the system is bled and that the actuators are opening correctly then it may need another pump to circulate water - does upstairs have it's own pump?

MrsQuestions

Yes. Down stairs has a pump and upstairs has another.

Should have asked earlier, but can you feel warm water flowing into the UFH pipes from the manifold and cold water leaving the manifold on the return? An airlock may be the problem.

MrsQuestions

No there is definetly no air lock. Water is flow out warm and returning slightly cooler.

MrsQuestions

MrsQuestions wrote: »

No there is definetly no air lock. Water is flow out warm and returning slightly cooler.

If the return from the floor coil is warm then there may be insufficinet heat transfer into the rooms, do you have thick carpets? can you feel any warmth in the floor?

MrsQuestions

I can feel the heat through the carpets. I don't have any really thick carpets.

MrsQuestions

MrsQuestions wrote: »

I can feel the heat through the carpets. I don't have any really thick carpets.

Sounds like the UFH is working OK, is the house well insulated?

MrsQuestions

Ya. The house is only 3 years old and we put extra insulation in when we were building it.

MrsQuestions

MrsQuestions wrote: »

Also, did he recommend how long the heating should be on each day. I was told to have it on from 6 to 8 am and 5-10 pm at 21 degrees in kitchen and sitting rooms. 20 in bedrooms.

Going back to an earlier point, have you tried runing it 24/7 for a while to see if the rooms come up to temperature - I'm aware that many heating designers only guarantee the systems reaching the design temperature when the outside temperature is 5 deg C (right now it's between 1 & -1 outside Athlone). That was the design temperature on my system as well, but extra insulation (as well as running 24/7) means that the temperature stays constant - doesn't use too much fuel either because I don't have the "warm-up" stage.

MrsQuestions

Sounds like thats worth a try. How long did it take your house to get up to temperature at the start?

The other thing is I don't have a buffer tank. I have heard this is good to have. Do you have one?

MrsQuestions

MrsQuestions wrote: »

Sounds like thats worth a try. How long did it take your house to get up to temperature at the start?

The other thing is I don't have a buffer tank. I have heard this is good to have. Do you have one?

From stone cold to temperature took about two days....Yes I do have a tank (thermal store), it also serves the DHW as well, it stops the boiler short cycling as it will have a long burn while the tank heats up and the UFH will not interfere with running of the boiler as the tank thermostat calls for heat as needed. A low flow rate through the UFH may cause the boiler to heat at a lower rate than it is capable of doing because it can't get the heat away quick enough.

MrsQuestions

I have contacted an engineer about having a buffer tank and solar panels installed. Hope to get it done in January.

What square footage is your house and what size is your buffer tank?

MrsQuestions

MrsQuestions wrote: »

I have contacted an engineer about having a buffer tank and solar panels installed. Hope to get it done in January.

What square footage is your house and what size is your buffer tank?

House is 190 m2 and the tank is 350 litres (I think) good idea about the solar panels.

ennisjim

Hi MrsQuestions,

If your problems persist you may be interested in talking to the heating consultant I used - though he's not cheap ! He is based near Athlone. PM me for details if interested.

By the way I also have a buffer tank (500litre) and 2 manifolds and 2 pumps, but since I've only just turned on the system (and only ran it for a day) I can't comment yet on how effective it will be.

yop

If you can feel heat through the carpets then i wonder why not in the room.
Not all carpets work with ufh, any chacne u cud roll back the carpet in 1 room for a couple of days?