Luke warm radiators

[ct75]

I have just moved into a house that I have been renovating for 18 months, I have mounted the boiler in the attic and it is brand new with a total of 14 radiators in the house.
Now when I turn the system on the upstairs rads get really hot and I have to turn them down to 3 on the thermostats, downstairs I am suffering from luke warm rads in most of the rooms which barely give off any heat, this is even though the thermostats are set to 5 which is the highest.
Does anyone know how I can alleviate this problem.

[buildersmate]

If you have done all this work yourself, then you presumably know about balancing the system?
If a tradesmen did it for you, he/she! should have done it.
The water flows around the system to different rad combinations using parallel flow paths. This means that the longer flow paths (to the downstairs rads in your case - furthest from the boiler) have a longer path and present more 'resistance' to the flow of hot water. In turn this means that the rate of water flow is less - so they don't get hot.
Balancing means turning down the lockshield valve at the OPPOSITE end of the rad to where the thermostatic unit is (with all the Thermostatics held wide open) so that it partically constricts the flow of water to the SHORT pathways, so that equal amounts of heat get distributed everywhere.
Google 'Radiator balancing' for more information on exactly how' - or get the contractor back if you've not yet paid him.

[ct75]

sorry, the work was done by someone else, he obviously has not balanced the rads properly.
Anyway that gives me something to go on and thanks for your help.

[simonruss]

depending how big your boiler is 14 rads is a lot for the average boiler! buildersmate is right, you need to force the water down to the furthest reads first.

[ct75]

Hi, I know 14 rads is a lot but i also know that the boiler can handle that as i did all the checks before purchasing it.
Thanks for the advice anyway guys.

[tezestwing]

this site is all about helping people but to do that we need as much information as we can get in the first post,this subject on balancing has been well aired of late so you should find recent posts on it hth Tez

[simonruss]

always make sure you have one rad without a trv on it. most people make this one the bathroom. that may help with balancing.

[tezestwing]

to comply with part L the room stat is sighted in the room that does not have TRVs on the radiator the bathroom would be a very dangerous place to have a room stat hth Tez

[simonruss]

the thermostat needs to be in a place where there is a constant temperature, not near a regularly opening door for example. As far as I know when I finished my NVQ Plumbing it doesnt matter if the room its in has a TRV on it or not as long as its sufficiently far enough from the rad for it to be unaffected.