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Plumberpro
Plumberpro, Home Appliance Technician
Category: Appliance
Satisfied Customers: 634
Experience:  Heating and hot water heating appliances experienced
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I am running underfloor heating using a Vaillant ecoTEC plus

Resolved Question:

I am running underfloor heating using a Vaillant ecoTEC plus 415 boiler. I have installed the correct amount of pipe for the area that I need to heat and the room thermostat is communicating with the controller and boiler but it seems as though the room never reaches the temperature set on the room thermostat as the boiler turns itself off (anti-cyclone mode?).
Submitted: 3 years ago.
Category: Appliance
Expert:  Plumberpro replied 3 years ago.
Plumberpro :

Hi . what floor finish dobyou have on top of the pipes

Customer:

Engineered wood

Customer:

The room reached temperature a few weeks ago when the weather was generally warmer - it's just now that it's colder and the heating is having to work a bit harder

Plumberpro :

Ok . what size pipe, and what is the pipe laid in . is the egineered wood sitting directly on top of the pipe ?

Plumberpro :

Hi . I a asking this as you probably know because there details are so important to the heat output

Customer:

It's sixteen mill pipe sitting on celotex (grooved) between joists, as I said it has worked ok before, I just don't inderstand why the boiler switches itself off before the room is up to temperature. (The floor is sitting on 18mm ply)

Plumberpro :

Hi . what temperature is the boiler set at , do you know? , thanks

Customer:

it has been set at 60c

Plumberpro :

Why not try raising the temperature up to 70 and see if if this gives more out put. I know the system is supposed to run at lower temperatures ,but with underfloor heating every system seems to work differently . you may have used 10 mm pipe and the low water content in the floor heats so quickly

Customer:

I set it at 70c about an hour ago and have had the room stat set at 24 degrees all day but even in the last hour the room temp hasn't budged above 21.5 (fine for me but not my wife)!

Plumberpro :

Reaching 21.5 is great. These systems are not really for high heat but a comfortable heat. You may not get it to 24 unless you add a radiator.

Plumberpro :

Or maybe try it on 80 degrees

Customer:

Maybe, but putting a rad back in would defeat the object of having UFH. I don't think the boiler will go to 80c

Plumberpro :

The boiler will definitely go to 80, I understand with the rad , though .

Customer:

I think it's the set up on the boiler - switching itself on and off regardless of the room stat asking for heat

Customer:

I have now set the boiler to the max (75c), it fired up, rose to 78 then dropped back down to 60 on the display on the boiler - it normally goes up to 60 then drops back down to 45 so I'll have to see if that makes a difference

Plumberpro :

Yes , you are right . set by the boilers inner thermostat. There is a way of overriding the Max heating temperature but I have been looking through the manual and can't find it

Customer:

Well, if you discover anything please let me know. Looking on the internet there seems to be a lot of criticism of Vaillant boilers' 'cycling' as in turning themselves on and off

Plumberpro :

Cycling is normal usually as it gets up to the required heat so quickly then shuts off , as the water temp lowers , it fires to heat it again. Its because they heat the water so quickly. I take it you have the heating dial set to max

Plumberpro :

Is it on max

Customer:

Hot Water temp is set at 60c, (same as the stat on the tank), I now have the heating set at 75!

Plumberpro :

That should be high enough, to be honest I don't really think there is a way of getting the high temp you need without looking at a rad.

Customer:

Ok, thanks for your time

Plumberpro :

Your welcome

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