Cold Radiator Furthest Away From Boiler

[hatcheth]

Hello,

We have had a problem double radiator ever since we moved in the house. The inlet pipe is always hot (too hot to touch for long) and the outlet pipe is always cold. The top of the radiator is slightly warm, the bottom generally stone cold. It is probably the furthest away radiator from the pump. The house had two small radiators added a few years after construction (built in 1994). It’s a standard boiler (not combi).

The troubleshooting steps I have taken:
1. Bled the radiator – no air in it.
2. Turned both valves off, removed radiator, hosed any debris out. No better.
3. Switched off all the other radiators in the house. The radiator gets very warm and works normally.
4. Gradually switched back on the other radiators – as each one gets switched on the colder the problem one gets.

The questions I have is:
1. I have assumed its not an air lock, because when other radiators are off its ok. Is this correct ?
2. If the other radiators are correctly balanced, would it be the pump that needs to be upgraded or the boiler ?
3. Anyone recommend any crude (aka cheap) ways of measuring the temperature of the inlet and outlet pipes to establish if they are at the correct temperature ?

Thanks in advance for your help..

Stephen

 

[clf-gas]

Your system was'nt balanced after addition of two new rads, follow this link.
//www.diynot.com/forums/viewtopic.php?p=243114#243114

 

[hatcheth]

Thanks for your reply.

I've read that page, but wanted to know if you have any crude ways of measuring the temperature. If its not possible to do it cheaply, any links to the appropriate temperature measuring equipment would be appreciated..

Thanks.

 

[clf-gas]

Very crude, I use a lazer thermometer.

Also contact thermometers will work, or probe.

 

[JohnD]

if your hands are like mine, the flow pipe should be "too hot to hold" and the return pipe should be "too hot to hold for long"

If not, you will have to buy a pair of Pipe Thermometers