Central heating Pipes and radiator issues

[Jag1978]

I’ve had a long standing issue with my radiators which are connected to my Valliant boiler. I moved into the house about a year ago and have only really started to use the heating system during the last few months. Now with a new baby in the house the heating is on constantly. Fitted a new Honeywell CM927 wireless stat to manage things.

My problem is that a couple of the radiators on the system are only heating up at the top but cold or lukewarm at the bottom. Before anyone says anything I did think of sludge. So the things I did were make sure that the system was bled properly which didn’t make much difference. Then removed the suspect radiator and flushed it out with a hose pipe in the garden… Hardly any muck in there, and still got the same issue.

I was looking at the pipe work for the whole system and noticed 2 copper pipes are feeding the heating system. I felt both pipes and noticed that one was very hot and the other was only hot. Basically couldn’t touch one and could hold the other no problem. Sorry I’m no heating engineer and my words are not very technical. The two main pipes from the boiler are bigger which feed what I believe are 15mm radiator pipes. The boiler pipes are both very hot and only one of the fed pipes are very hot, as I said the other fed pipe is only hot. Could this be the reason why the heater is not working at full capacity. I’m assuming that one of the pipes is used to feed the water and the other is a return. I’ve also noticed that it takes time for the radiators to get up to heat. I’m not sure if it’s normally but my boiler can take ages of continuous running to reach 80 degrees otherwise it just floats at around 45 – 50 degrees.

Advice much appreciated

Regards

Jag

 

[Agile]

There seems to be a flow problem but you have not given us the boiler model.

You may have an open bypass.

To help we need a lot more information.

Tony

 

[Jag1978]

Sorry for the lack of info..

It's a Valliant Turbomax 824e. No idea if it's an open bypass

Regards

Jag

 

[D_Hailsham]

I was looking at the pipe work for the whole system and noticed 2 copper pipes are feeding the heating system.

Are you talking about the pipes from the boiler to and from the radiators? Or are you talking about two pipes which disappear into the loft - one about 15mm diameter, the other slightly fatter?

 

[Jag1978]

No the two that come out of the bottom of the boiler both much bigger pipes maybe an inch or so... then there is a 15mm pipe on each main pipe which flows off them, these are servicing the radiators

 

[D_Hailsham]

I'm still confused. Can you post a pic or a drawing showing the pipe arrangement at the boiler?

How many rads do you have?

 

[Agile]

Just because you flushed out the radiator thats not always the solution.

Have you done the "bucket test" ? See FAQ on this site for details.

Tony

 

[racket]

Could the system need balancing?