How hot should a radiator get

Jim Kernsey

Hi

I recently had a conservatory built on the back of my house, they installed a new radiator along with it.

I have Gas central heating and the new radiator runs off the main system.

The weather has been generally good since they finished the conservatory so I haven't had the heating on in it much, but today I noticed that the new radiator is not getting as hot as all the others.

It is getting relatively hot, but my concern is that come mid winter the radiator won't have enough power to keep the room warm.

When they were installing it they had a choice of old radiators to get a feed from, they picked the nearest one, which is generally the weakest one in the house.

I don't want to seem like a moaner, but it cost an awful lot of money to put it there, and if it’s not going to be able to heat the room, what was the point in shelling out all that money?

As I said it is getting relatively hot, but perhaps not hot enough to warrant it being there at all.

Should I just accept that the heating system is just pushed to the limit, or should I suggest they take a feed from a different radiator?

Advice Appreciated

JK

astec123

Have you used the Blead valve? could be full of air! Otherwise it may be that the valve on the side is still not fully open or that the boiler is set down, I know that I sometimes hit off it and accidentally turn it down to about 40 so the house goes mighty cold.

kadman

astec123 wrote:

Have you used the Blead valve? could be full of air! Otherwise it may be that the valve on the side is still not fully open or that the boiler is set down, I know that I sometimes hit off it and accidentally turn it down to about 40 so the house goes mighty cold.

Did they balance the lockshield valve ( the cold return outlet ) with a temp guage . This maintains the correct temperature output of the rad. There is no reason why the rad should be noticeably cooler than the other rads, if its properly set. The thermostatic valves only open and close at set temperatures. The lockshield valve regulates the flow of water through the rad, this is of equal importance.

You are dead right , you have paid to get an acceptable output from that rad, and I would try and resolve the issue with the plumber, in a friendly manner first. Was it sized by the plumber, or just dropped in by the builder.

kadman

Jim Kernsey

astec123 wrote:

Have you used the Blead valve? could be full of air! Otherwise it may be that the valve on the side is still not fully open or that the boiler is set down, I know that I sometimes hit off it and accidentally turn it down to about 40 so the house goes mighty cold.

I've bleed it, no air in the system.

Kadman
tell me more about the lockshield valve

Cheers

JK

rooferPete

Hi,

It appears you need a good plumber preferably heating specialist to balance the system.

A properly balanced system will give you the same heat in the radiator nearest the boiler and the radiator furthest from the boiler.

Kadman is right when he says the adjustment is made at the lockshield valve, however if you don't know what you are doing you could end up taking the heat from other radiators to heat just one.

It could take a diy job as long as two days to get the system near enough to performing correctly.

There is the possibility when the rad was installed there was air in the system which gave the installer a false reading, especially as the rads are manual and not fitted with thermostats.

kadman

Hi Jim,

The lockshield valve varies the flow through the rad , and thereby allows the rad to radiate the heat into the room. You may be heating your water to the maximum, and your inlet valve fully open, but if the lockshield valve is only partly open, you wont get the maximum output of heat.


As Rooferpete rightfully pointed out , a good plumber will identify and balance that rad in minutes. At least then you can proceed to rectify the problem. Unless you are familiar with plumbing , the setting is best left to a pro. He could also check all the lockshield settings through out the house, for maximum efficiency.

kadman

Lex Luthor

Jim,

I hade the same dilemna as you a few years back when my extension was built and the 2 news rad that were connected to the last rad on the system barely got hot enough. I had to go and balance the whole house rad system. I did it myself but it took the whole weekend. I referenced this page http://www.diydata.com/projects/centralheating/balancing/balancing.htm
I got myself a digital multimeter from work with a dual K-type thermocouple on it so I could get both temps at either side of the rad simultaneously.

The problem you are having is that the first 6-7 rads in the house are taking all the hot water and by the time it gets to the last new ones, all the heat is gone out of the water. By balancing them, you are basically reducing the amount of hot water entering the first few rads to enable the hot stuff to get to the last few.

I also changed the nozzle on my oil burner to a slightly larger one, increased the oil pump pressure slightly to give me a higher BTU output from the boiler and flicked the switch on the water circulating pump to the next higher setting.

Jim Kernsey

Thanks lads

sounds like you've hit the nail on the head, at least i know that there is nothing major wrong, so i'm happy to go ahead and tile the floor around it.

There's no major rush on getting it sorted.

thanks for your advice