TBOE radiators in new build incorrectly piped

[chris watkins]

Ok I have a response.
They contacted the manufacturer stelrad and they told them they need to swap the flow and return.
I have also asked them to resolve the incorrect flow temperature as it should be much higher.

So hopefully all will be resolved, it is a wonder this into web thing.

 

[Pickwickpick]

Ok I have a response.
They contacted the manufacturer stelrad and they told them they need to swap the flow and return.

I have also asked them to resolve the incorrect flow temperature as it should be much higher.

Good result, do hate how these developers take the pish so badly, you really shouldn't have to fight that hard for them to provide a pre agreed upon service/result!

 

[ImranF]

To be honest, most people wouldnt even check. As long as their rads get hot they would be not realising there is a problem.
Anyway they also have to resolve the fact that there is a lot of air in the system. Not sure how power flush is going to solve it. Assume their must be air ingress from somewhere.

 

[chris watkins]

Anyway they also have to resolve the fact that there is a lot of air in the system. Not sure how power flush is going to solve it. Assume their must be air ingress from somewhere.

Check the inlet side of the pump & pipe work until you get to the expansion vessel.
What is the pump set to ? (let me guess fixed speed III)

 

[John.g]

That's interesting.
Perhaps the developer looks after the secondary circulation as well? and has a flow meter plus the flow and return temps to calculate the energy usage for each user billing purposes.

 

[ImranF]

There is a meter on the pipework in the heat unit. Now I will try to figure out how that actually works.

 

[John.g]

If they are serious about accurate energy consumption then they would have to measure the deltaT as well. Is the bill presented as kWh/month? Or what and purely for comparison purposes you might like (or not) to post one period's usage.
Any circ pump visible there?.

 

[ImranF]

They provided pay as you go meter. This is only for hot water and heating. I have standard meter for electricity.

For months where I don't use heating it costs £20 a month. During winter it cost me around £60 a month with the inefficient setup.

Basically this is for a family of 4.
Also I know they take £10 a month in service charges to cover for the gas in the central plant and for maintenance of everything including the unit in the flat.

This seems far more expensive then gas boiler.

I will look at the Meter and check the KW usuage. The rate is at 7.9p per unit used. I believe there is a daily charge of 20p a day. So around 6 to 8 KW a day usuage.

I am quite Fortunate, apparently one bedroom flat was paying more than us to assume something is wrong with his meter.

 

[John.g]

You are doing very well, I would have expected at least ~ > 30 kwh/day for HW+CH. If you are/were using say 7 kwh/day for HW only; this equates to a usage of 30 ltrs/person/day @ 60C or 50 ltr/person/day @40C, pretty normal/lowish usage IMO.

 

[John.g]

Hadn't copped on to the£60/month in winter which would equate to ~ 25 kwh/day for HW+CH, quite good.

 

[ImranF]

Plumber is here now. He said 53 degrees flow is fine for the flow. He said 70 degrees would be too hot. That means the radiators must be oversized as the are delta 50 rads.

 

[John.g]

Has he plumbed the rads TBOE now?.

 

[ImranF]

Doing it now. So let's see what happens.

 

[ImranF]

Ok works completed. 58 degrees on the flow and the return is 52 degrees. One thing we noticed, radiators can be bleed of air and the system has no air anymore. Silent central heating for the moment. Radiators are much more hot to feel. Still don't think they are running at full potential and to be honest he should have atleast balanced them as there are temperature variations between flow and return between all rads.

I will leave heating on for atleast an hour a day to see if air keeps returning in the system.

Does anyone think that the flow temps should be higher but don't forget that we have district heating system. Input Temp is around 80 degrees so not sure if heat exchanger can heat the cold water to 70 degrees. Engineer mentioned that the water in the radiators would be higher than what he is seeing on his thermal camera.

 

[John.g]

You have, (58+52)/2)-20, "35 deg" rads which will output 63% of 50 deg rads, the rads may have been over sized to take account of this, who knows?. If you gave dimensions of a room and the dimensions of its rads then someone on here would have a fair idea IMO as to under sizing or not.
I see you have 2 rads in a 30 M2 L shape so maybe you can just post the dimensions of those two rads.

 

[ImranF]

My main concern now is my daughters room. I believe bthey have have undersized the radiator as it's only 600 X 600. It's stelrad compact K2 I believe. Output is 3100 BTU. Room size is 14.25 by 11.25 ft.

Room has two external walls and one of these has a French door leading to balcony which is around 2m by 2m in size.

Problem is I don't think they will ever change the size of the radiator.

Open Plan will be ok as we also cook there.

 

[ShaunCorbs]

ask for the heatloss calcs

 

[John.g]

My main concern now is my daughters room. I believe bthey have have undersized the radiator as it's only 600 X 600. It's stelrad compact K2 I believe. Output is 3100 BTU. Room size is 14.25 by 11.25 ft.

Room has two external walls and one of these has a French door leading to balcony which is around 2m by 2m in size.

Problem is I don't think they will ever change the size of the radiator.

Open Plan will be ok as we also cook there.

From your info you have a 0.91 kw rad ("50deg") heating 14.9 m2, but because of lower running rad temps you only have a 0.57 kw rad ("35 deg") and I doubt very much if this was the design heat loss for this 14.9 m2 (38watts/m2).
You would need a ~ 60% bigger rad to compensate if a 50 deg rad was their standard.
As stated above it would be nice to get the heat loss calcs.

 

[chris watkins]

Don't take any more old crap about this from them, ask for the heatloss calculations for your property so you can see what is require & ask them once again to install them as per the designs.

Post 22, always the starting point !!!

 

[ImranF]

Hi, I never responded but thanks for everyone's input, help and advice. Eventually might change the radiator in my daughter's room but will leave it for now. Developer never ever responded with heat loss calculations. I think it is simple enough to upgrade the radiator and be done with it.