problem with underfloor electric heating

[daveaztec]

Anyone ever encountered problems with underfloor heating thats not been insulated with warm up times and temperature etc ?

 

[DHTiling]

Hello Dave and welcome...

Can you give us some more info please..


UFH type...board type and type of thermo sensor..?..

 

[david campbell]

:welcome:

 

[jay]

:welcome: what probs are you having

 

[Diamond Pool Finishers]

hi:welcome:

 

[Dontiler]

:welcome:

 

[White Room]

Hi and welcome

 

[Ajax123]

Hi Daveaztec. I can imagine there would be problems with leccy UFH under tiles if no insulation cos the specific heat of the concrete su base would sap all the heat out of it. It will take ages to warm the floor. More detail would be useful to diagnose the problem though.

 

[faithhealer]

a builder told my customer to leave it (ufh) on for two days too warm up!!! Fitted correctly with insulation boards and now takes 45 mins. (and in a freezing conservatory)

 

[daveaztec]

irecently installed a 600w loose wire heater on an 4.4m2 uninsulated concrete floor,10mm porcelain on top,this took 4 days to reach a temperature of only 28oc,the customer did not want insulating board as this would have created astep into the room. The manufacturers manual say 5-8 hours.The wire was layed at correct spacings 90mm. Having had many "UNHEATED" ! conversations with the manufacturer regarding the information regarding the "recommendation" of insulating boards being used, I have told them that the information given in the litreture is wrong and misleeading and that the boards are a necessity!!!! The whole floor has to be removed,boards installed,newloose wire system,and retiled, all at my own expense,except for the new ufh which the manufacturer is suppling FOC:hurray:I am installing a800w heater now as the extra wire o.1m2 can easily be lost under a free space on the floor,the wire can be layed at 60mm spacings insted of 90mm to prvide more heat per m2 and a extra 200w of heat for the whole room. So inslallers beware of manufacturers recommendations they may be a nessesity in certain situations

 

[jay]

:8:thats interesting did you bring the heating on slowley and a new floor will always take longer all the moisture to remove also reducing gap between wires would make a lot of diff is it norm to run at 28 c and thanks

 

[diamondtiling]

irecently installed a 600w loose wire heater on an 4.4m2 uninsulated concrete floor,10mm porcelain on top,this took 4 days to reach a temperature of only 28oc,the customer did not want insulating board as this would have created astep into the room. The manufacturers manual say 5-8 hours.The wire was layed at correct spacings 90mm. Having had many "UNHEATED" ! conversations with the manufacturer regarding the information regarding the "recommendation" of insulating boards being used, I have told them that the information given in the litreture is wrong and misleeading and that the boards are a necessity!!!! The whole floor has to be removed,boards installed,newloose wire system,and retiled, all at my own expense,except for the new ufh which the manufacturer is suppling FOC:hurray:I am installing a800w heater now as the extra wire o.1m2 can easily be lost under a free space on the floor,the wire can be layed at 60mm spacings insted of 90mm to prvide more heat per m2 and a extra 200w of heat for the whole room. So inslallers beware of manufacturers recommendations they may be a nessesity in certain situations

A 90mm gap between the wires would just take the chill off the floor, without insulation boards it will struggle to do anything at those space sizings. Loose cable is installed after you have calculated the area to be heated. You dont just buy a kit and hope that it will cover any size floor, you have to order the appropriate length of cable. 60mm is the norm to obtain a heated floor over the correct insulation. As for the laying of the insulation boards your customer said they did not want them so why are you having to re lay the floor at your expense?
Your cable should have been 73mtrs long to give a 60mm gap and you should have advised them that it will just give a minimal amount of heat without insulation.
They chose the cheap option here not you.

:mad2:

 

[daveaztec]

Yes but the recommended gap for a 4.4m2 square floor is 90mm with the 600w heater and the area was exactly 4.4m2,the manufacturer has advised me that they will be reviewing its marketing and installation instructions,l have installed many of these systems and the first time l have encountered a problem,just shows that 0.1m2 can make a lot of difference to the heat transfer to the floor

 

[diamondtiling]

Dave who was the manufacturer of the cable mate? Going on your heat area of 4.4 mts and having a 90mm gap is a cable of 49 mts in length, massively short for the rooms requirements. I think you should have insisted on the insulation otherwise its money down the drain.
I still cant work out why you are having to fork out for this work?

:incazzato:

 

[faithhealer]

I agree with Dom, why do you have to pay for it dave. Sounds like you advised boards and they turned it down!