Radiators not heating properly

[Tweety]

Hi,
I was wondering if anyone would have any information on this. The radiators upstairs in our house (which is only 6 years old) do not heat properly. The downstairs rads are fine and get quite hot. However, upstairs the top quarter of the rads get hot but the bottom 3/4's do not heat up. I know that if its the opposite i.e. the bottom heats but the top doesn't, then it means the rads need bleeding, but we are unsure what to do it in our situation.

We have had plumbers to look at it already and they have said that they feel its because the pump isn't strong enough. However, some of the rads used to heat better but have deteriorated over time. Also, the plumbers cannot guarantee that even if we get a new pump (which I think will cost several hundred euro), it may not solve the problem.

I read somewhere that it may be sediment that builds up in the rads preventing them from heating at the bottom. Does anyone have any information or experience about this?

Thank you!

 

[xt40]

have you checked that there is no air in the system by bleeding the valves.
if that doesnt work, check for a blockage (air or sediment) by switching off all the rads and switch them back on one at a time , bleeding as you go which will increase the pressure upstairs and possibly shift it.
if the system is fed by a seperate mini water tank in the attic, theres probably enough water in it as it would refill automatically, but if its a pressurised system, and was lacking water, it doesnt refill on its own. for that theres a valve in the hot press probably with a pressure gauge on it
.if you have one of those, open it up before bleeding the rads. if theres water flowing, it will probably make a fairly noticable noise

if downstairs is heating up, the pump is probably ok but if not,
a new pump costs 55 (heatmerchants brand)-85(grundfos brand) euros from heatmerchants, not hundreds. swapping it is not a big deal
switch the power off at the mains
tie up the ball valve in the attic if you have one
drain out the ch system outside at boiler (if its oil)

undo 2 pump nuts with a big stilson wrench
clip 3 wires into the new pump (same as a 3 pin plug)
refill the system
allow maybe 2 hours for this i8n total of which 5 minutes is for changing the pump

 

[pnh]

I just had my heating upgraded-it was completly drained and flushed and an inhibitor put it.I had a problem with 2 rads which had become sluggish and the guy explained-that sludge and gunk can build up in rads over time and form a kind of bridge restricting water flow.He also found a faulty TRV which he replaced.
If it hasnt been done for a number of years-suggest u think about having it done.Its worth it