Radiators giving different levels of heat? Also banging pipes

kdouglas

Just wondering if anyone has any input on this...

There are 4 radiators upstairs, Master bedroom, back bedroom, box room and bathroom.

Bathroom and box room radiators get quite hot to the touch.

Master bedroom and back bedroom radiators seem to only get warm and not properly hot enough.

What are the possible causes and how do I go about fixing it?

The back bedroom is not really used at the moment, was thinking of turning off this radiator to see if it helped with heat getting to the master bedroom, but surely all radiators should heat reasonably evenly?


Also, when the boiler kicks in and starts pumping around the house, I can hear some pipes clicking/banging, not particular loud, but the two main locations for it seem to be on either side of our bedroom, so when the heating comes on at 6.30ish to warm the house and water before we get up, it sometimes wakes me up. Again, what are the causes here and what can I do to fix it?

Any advice appreciated.

Edit: Just thinking, If I can figure out fairly closely where the pipes are knocking, drill a (approx 8-10mm) hole in the floorboards and use this to pump expanding foam around the area, would it secure the pipes and prevent knocking?

GreeBo

The pipes are expanding and are probably rubbing against each other or the floor boards/joists.
Shut down the rads that are hot and see does that help the cold ones.
Also have you bled the cold rads?
If they are hot at the top but cold at the bottom in a triangle pattern then they are probably full of gunk and need to be flushed or replaced.

kdouglas

Tried bleeding those two radiators last night and just got water out of them.

The radiators were a little cool when i checked but they seemed to be in a slightly triangular pattern alright.

How does one go about flushing them? Drain the system, remove radiator and bring it outside?

GreeBo

kdouglas wrote: »

Tried bleeding those two radiators last night and just got water out of them.

The radiators were a little cool when i checked but they seemed to be in a slightly triangular pattern alright.

How does one go about flushing them? Drain the system, remove radiator and bring it outside?

Pretty much, but if you just shut both valves you dont need to drain the system. Get a shallow bucket to take the water out of the rad before you try to get it outside, also cover the open ends as you wont believe the black crap that will drip out.
A powerhose is probably required also.

kdouglas

Thought as much, we were thinking of changing the radiators anyway since they are only single radiators in reasonably large rooms, so probably just get new ones and replace.

Should replacing a single for a double be a fairly straightforward swap or will I have to make sure the heating system has the capacity/pumping power for it first?

GreeBo

Your boiler should have spare capacity but if you are changing a few of them you may need to check.
The boiler should give its output in BTU's somewhere, you then need to figure out the BTU requirements of each room and purchase the appropriate sized/output rad (you might not need a double)

There are lots of BTU calculators on the web, you just input the room dimensions, type of room and some other factors (double glazing, orientation, insulation etc)

Then you just head off to your local providers (Heat Merchants etc) find out what make of rads they supply (Stelrad, Myson etc) and match the output to the size of rad you require. Different styled rads will have different output.

Its handier if you can get the same sized rad again, otherwise you need to start moving pipes etc.

travist

hi

Were you able to sort out your knocking radiators?

I have a similar issue and wanted to see what is the best way to go about resolving. thanks