Please explain my radiators?

[Wellspankmybottom]

I live in a large 4 bedroom house with 14 rads of various sizes. My bedroom on the top (2nd) floor has the first rad in the chain (boiler/megaflow in the loft crawl space). The boiler temperature is at 72C. My bedroom rad is only hand-hot at the top and cool at the bottom, the ensuite rad is the same. The rad in our downstairs bedroom - ground floor, (something like 10th in the chain) is piping hot all over. Why the disparity? My bedroom rad has a thermostatic valve, currently set to the maximum setting. The temperature in the room is 16C!!! Help please..

Sounds like En Suite & Bedroom need bleeding. Maybe the downstairs 10th one is the main radiator.

Anyway PigletJohn is the wo/man to ask. He/she knows everythiiiiiing &, I secretly love them for it

Yes, you probably need to bleed your rads.

My research from the past few days suggest cool at bottom means that there is sludge in the radiator (cool at top would indicate it needs bleeding). Our bedroom one is stone cold all over so still haven't fixed our problem. Good luck!

The system was flushed about 6wks ago when I had some work done. It's definately not a bleeding problem, that's fine. Could it be that the valve, despite being on 'max' is actually not & is only letting a trickle of hot water through? -Hence the cold bottom?

Do they need balancing?
(I don't really know what I am talking about)

we always had bother with our two top floor rads..never really hot and the one on the landing below was unreliable also

anyhoo...we had a new, smaller rad in the sitting room, and the landing one was also replaced and now they are all lovely and toasty

are all your radiators new ish?

Just asked my DH (he's a commercial plumber and gas engineer). He says it could be your TRVs (thermostatic rad valves) are sticking slightly (take off the heads and push the pin in and out/up and down).
Its most likely that your whole system needs balancing following it being flushed. This is done by turning down (not off) the rads that are getting hot, you turn them down on the return valve end i.e. this is the end that's opposite the TRV (you may need a spanner for this). This restricts the flow through the the hottest rads and so forces the hot water to the cooler rads. Having your system flushed out also doesn't guarantee that there aren't blockages in your system. Hope this helps.

warm at the top and cold at the bottom is most likely radiators that need balancing.

Try www.mumsnet.com/Talk/property/a2205419-New-radiators-not-getting-hot#50023831

This is a useful thread! I have two radiators in the conservatory that have this problem, might have to try the balancing thing.

Zogs we had one radiator that was stone cold, we found the pin on the trv (thermostatic valve) was stuck. You tube it and you will find good instructions on how to free it.

We live on the 4th floor, our radiators need bleeding every week or so being high up

cold at the top and hot at the bottom is air that needs bleeding.

But if you have to do it every week there is a fault.

Piglet - its in a communal heating system so I don't think we can do anything about it from our flat except bleed them weekly in winter

Missy Thankyou. Turns out system needs to be flushed (parts of the pipes are cold as well)

Artandco - have you tried complaining about this? If you're having to bleed your radiators weekly they probably need to retrofit some AAV's.

Do you not have a plate heat exchanger to separate the communal heating system from the system in your flat?

What's a plate heat exchange? What's AAVs?

We literally have a huge megaflo in flat and that's it. It's auto set to 21 degrees. So we can only turn radiators on or off at main radiator

Just looked up aav not sure where that would fit in our flat or go? It's says usually in the roof ( it's a flat roof), and that it's only used in 2 storey places usually

Oh I don't think we have a plate heat exchanger either

Have you tried checking the pressure. Daughters radiator in lift was like this so I highered the pressure and it's been fine since.

AAVs are automatic air valves, they go on the highest points of the heating system to remove air.

The Megaflow should separate your system from the communal heating system, so it being a communal heating system wouldn't be causing the air in the radiators. (It's not the same water flowing around the system, only the heat is transferred.)

Speak to whoever installed the system, if it's fairly new they might rectify it under warranty. You shouldn't have to bleed the radiators weekly.

I'm assuming the flat company fitted it, its at least 10+ years old as we have been here that long. They take weeks to fix anything and we aren't allowed to use outside contractors. Which is annoying as then have to book whole day off as they arrive 7am-7pm, sometimes they cancel at 6.30pm meaning a wasted day off for nothing