UNDERFLOOR HEATING

[mrcrow]

i have a piped water underfloor heating to 3 zones in my house.
there are only temperature control points in 2 of the rooms, dining room and lounge. the kitchen area doesnt seem to have one.
i looked at the piping and see the 3 pipes with wired components on the returns which i assume are linked to control points.
the outer two of the wired components were not screwed down on the fittings: (as one might slacken off a thermostatic valve on a regular radiator) and i have tightened them up similar to the middle one.

the wires from these three components go into a control box.

on the supply pipework each supply has a flow meter. they look a bit gunged up to me and only the middle one seems to have any movement inside of the flow indicator.

photos uploaded to show the installation.









i suspect all is well but ask if there is any maintenance needed to the system especially the flow meters.

there is also a large valve with a red top and on it with the words 'click' and arrows pointing +1*C and -1*C

i am having a service done on the boiler soon and need to know if this is something i need to ask to have checked out.

cheers
geof

 

[Gasguru]

Looks like the temperature is off the scale...should normally be no more than 50 degrees or so. Post a picture of the thermostatic valve on the manifolds.

 

[mrcrow]

Looks like the temperature is off the scale...should normally be no more than 50 degrees or so. Post a picture of the thermostatic valve on the manifolds.

hi Gasguru
thanks for the reply
here are pics of the 'off' boiler temperature and the dial on the UFH ie ..no demand
also a shot of what i thought was a thermostatic head on the manifold







when i was checking the temperature of the system set on full demand the boiler would go up to around 66 then oscillate up and down around 10 degrees as the UFH gradually heated up the rooms.

when i use the upstairs radiators the boiler will go to 88

if that shot of the T head isnt what you want let me know and i will go snooping around to find the one you want..

ps the T head was 'loose' when i did the full heat test on the UFH along with one other and i tightened them up finger tight

now the system is 'cold' they were very tight to get off..should they be installed cold or hot??..could be i had them tightened down too far in the hot test?

cheers
geof

 

[mrcrow]

is this red knobbed item the thermostatic valve to blend the UFH supply to give 50*C?

the UFH is supplied from the same boiler as the radiator system and hot water
and is controlled by one programme...not split

 

[Gasguru]

Your combi will kick out heat to the radiators and U/F manifold at the temperature set on the boiler. Since the U/F pipework should be run at a low temperature the red valve blends boiler water with returning U/F water. Try adjusting it to give a temperature of say 50 degrees. The white heads are actuators for each loop and should be screwed down onto the manifold valve pin.

Unfortunately most U/F systems are never designed and installed properly. Better to have a programable thermostat just for the U/F zone. Should really have an overheat thermostat on the manifold to shut off the pump (or a zone valve) when the thermostic mixer fails.

 

[mrcrow]

Your combi will kick out heat to the radiators and U/F manifold at the temperature set on the boiler. Since the U/F pipework should be run at a low temperature the red valve blends boiler water with returning U/F water. Try adjusting it to give a temperature of say 50 degrees. The white heads are actuators for each loop and should be screwed down onto the manifold valve pin.

Unfortunately most U/F systems are never designed and installed properly. Better to have a programable thermostat just for the U/F zone. Should really have an overheat thermostat on the manifold to shut off the pump (or a zone valve) when the thermostic mixer fails.

thanks again Gasguru
i had the heating engineer round today as the underfloor heating wouldn't come on at all...he diagnosed and changed the motor in the zone valve and away it went...then it wouldn't go off when the room stats clicked off..!

after checking out the wiring he noticed the motorised heads on the return piping were jamming on the down cycle so he eased them and got them to all click off on the down stroke...there are little red sliders to show their progress..

we reset the room stats to fire up again and it took 6 minutes since the heads were slow to go up...

the system hasn't been used for 18-24 months as the previous owner died and the property lay empty till we bought it

so its new motorised heads on friday and hopefully got rid of all the gremlins which have gradually been eliminated over the last 3 weeks... dead fan, leaky gas valve...then now zone valve for the ufh.

and as you said he adjusted the red topped valve to get the uf heating to run at 50 when the boiler was running at higher temperatures

we have the ufh on now to check it out and he showed me how to 'ease' the motorised heads to get them all to click on and off till the new ones get fitted

all in all i really appreciate your attention and advice...many thanks



geof