Danfoss TRV Help

[toshtastic]

Hi,

I think that all my TRV's are set to cut off at 18 degrees - is this possible? No matter what setting I put my TRV on, the room never seems to go much higher than 18.

I would think that I should be getting to the low 20's on my highest setting.

I found the invoice for the installation of the system (done before I moved in) and on that it lists all the radiator sizes AND a temperature of 18 degrees.

I have heard that some TRVs have a pin or something in them that sets the max temp - is this correct?

The TRVs I have are the RAS-C Combis (013G6006), Angled 8/10mm valves

Any help is greatly appreciated

Thanks

 

[gas4you]

Sounds more like undersized radiators to me from where I am sitting.

I use these trv's a lot and have never encountered this problem

 

[kirkgas]

have you checked boiler setting? a TRV is used to cool a rad down from a high boiler/system setting not to heat it up, a few customers seem to think a trv at 5 should heat the room even when the boiler is set to minimum, try adjusting the boiler stat to see if it effects the rad temp as a starting point

 

[toshtastic]

hi

My rads are the right size as far as I can see. I have turned the boiler up and that has made a difference.

You are correct though, Im not 100% on how to work a combi boiler & trvs - Im new to them.

I just didnt think I would need my boiler up as high to get a decent temp from my rads. I have most rads on the highest setting (which should be the C for continuous as far as I can tell) and therefore I thought that the thermostat should be controlling the heat and my TRVs should basically do nothing

Cheers

 

[JohnD]

when your TRV reaches its pre-set temperature, it closes, and stops accepting hot water into the rad, so the rad and pipe cool down.

Is that what's happening to you?

Maybe your rads are just too small and in this cold weather they do not have enough capacity.

Presumably you keep the internal doors closed when the heating is on?

You can calculate heat losses per room, and radiator outputs, if you want, to see if they are undersized. But you can get an idea by eye, just looking at the sizes or rads and rooms and windows and knowing which are outside walls. Lots of rads are undersized.

 

[gas4you]

If you have a digital display for the boiler temp, it will need to be set to at least 60C, maybe 70C.

If it is just a standard dial stat, set it to about 3/4 the way round to full.

 

[toshtastic]

hi guys, thanks for all the replies

My rads are all correct size(well according to the calculation guide on the B&Q site they are), I have turned my boiler up to about 3/4 and I will keep an eye on it - cheers, I just figured that the higher I have my boiler then the higher the cost.

I wrongly expected that a lower setting on the boiler would just take longer to reach my desired temp

It could just be the fact I have an older house with cavity walls, but I would just have expected the temperature to get into the 20s.

Is the fact that 18 seems to be the cut off point and the fact that the invoice had a temp of 18 degrees written on it that strikes me as strange - may be a coincidence though

I do close all doors etc as well

thanks again for the replies