Daisy Chained Rads not heating up

[stevebamford]

Hi Plumber Types

We had a new heating system 18 months ago and the plumber fitted 3 small radiators under the bay window. These are piped together. ie only one feed/return connection for the 3 rads - thermostatic valve on one end

Only the right hand radiator heats up (this has the thermostatic valve on it) - the other two barely get lukewarm

The bay is the furthest from the boiler

Is this likely to be just a case of balancing - or is that setup fundamentally wrong ?

Many thanks

Steve

 

[sooey]

Did they work when they were fitted?
Have you bled them ?
Are the pipes 15mm?

 

[stevebamford]

Thanks Sooey

I don't think they ever worked that well (And yes I probably should have got the installer to sort it then but we've had a mad time with renovations, getting married and having babies!)

Ah yes - bleeding would be a good plan - but even the rad that works - its seems to be one end that heats up rather than a top/bottom split - I will check the other ones though

Mostly it was plumbed in 22mm - with 15 mm near the ends of the runs

 

[Nige F]

Are they piped together @ the top as well as the bottom What happens if you take the head right off the thermo valve - and unscrew the lockshield @ the other end -fully

 

[Bon]

In principle, the set up should work (despite the fact it would have been more straight forward to pipe all 3 rads in parallel from a balancing point of view) as it's in effect a mini 1-pipe system.

Is it the 1st or the last rad in the run that's getting hot?

You say the bay rads are the furthest rads from the boiler, have you tried increasing the pump speed?

 

[stevebamford]

Thanks guys

no just piped at the bottom

will try fiddling with the lockshields + valve tonight

 

[stevebamford]

ah ha !

opened the lockshield a bit and it is now heating up - just hope it hasn't altered any of the other rads

Thanks for your help folks

 

[TicklyT]

If the rads are only piped together at the bottom, I would expect the rads to get progressively cooler as the water flows through each in turn. Piping top and bottom would allow the feed to distribute more evenly between the three rads.

However, if it aint broke, dont fix it.