Why do my upstairs radiators not get hot?

hi i realise your problem might be solved by now, but if is not i can tell you what the problem is:

1. it might be blockage in the pipe whith ussualy does not happen whitout reason
2. your boiler propably is overloaded - additional radiators were added on to the system and there is not enough presure for the water to consantly circulate.

we had the same problem, radiators got heat at first then just became cold again

monk
January 2010

air vent is not the problem and repiping cold feed wont help air pips or aavs in loft if u have one will help to make sure system is full but dont think will help if the boiler is overheating that quick check out the boiler stat i think u will find its letting the boiler overheat if the pipework doesnt go across loft then dont bother with air vent as any air in system will go to rads and any air in pump area will go to dhw vent when u demand hot water when the boiler overheats look at the open vent pipe its the one that goes over the top of the f&e tank see if its letting water out or getting very hot again would point to boiler stat

sean
November 2009

The engineer also said there is no air vent on the central heating side of the system - there is one present on the hot water side just before it goes into the hot water cylinder. He is going to be re-piping the cold water feed and fitting a air vent to the CH side. We have no CH, no HW and we are getting desperate. The boiler overheats minutes after it switches on - even on HW - like there is such an airlock there that nothing circulates. When I bleed rads there is water there. Pump is basically brand new and has been checked with another unit. Thanks for feedback

Tammi
November 2009

the f&f tank lvl is really not a problem unless it is empty and the cold feed pipe isnt a worry unless it is blocked although microbore is a bit on the small side as a general rule its 15 mm sometimes 22mm you would know if it was blocked as the rads wouldnt fill upstairs when u try to release the air
u did make sure the trv,s are open? i just cant understand why an engineer cant solve the problem on sight, with more information i could probably solve it pretty quick, is the boiler sighted downstairs? r u on a H plan and if so is it high enough above the pump as to close to the pump will cause a problem with airlock is the bypass valve open to wide as this will cause some rads not to work check these out get back to me

sean
November 2009

We have had another engineer have a look, and he says that the feed/expansion tank water level never drops and it should drop slightly when the system runs. He noticed that the cold water feed from the header tank connects to the heating system after the circulating pump and it should be before - does this sound right? He said the piping from the header is also too thin - it should be 22mm and it is only 10mm Thanks for the feedback Sean

Tammi
November 2009

have u tried balancing your system close the lockshield end of your rads throughout and turn them all open about 3 rotations check your pump it may b going round but the fins might be worn check your heating isnt going into the water circuit via the 3 port

sean
November 2009

We are discovering the true meaning of the words "buyer beware" as we have just paid a gas-safe registered heating engineer £300 for a power flush and the heating system is still not working. He wants to install a completely new system for £3800 which I think is rediculous - why can't he find the fault? Any help would be much appreciated. Thank you for all help offered.

Tammi
November 2009

Tammi,as I said in a previous post I suspect you have a blockage in the pipework or an air lock.Very dirty water in a header tank normally means there is a circulation problem and 'pumping over' which means because the pump can't release the heat into the system it blows it into the header tank up the vent pipe.An airlock can cause the same problems.
I strongly recommend you get a heating engineer to take a look at it before you cause damage to your boiler.You may need a power flush if it's very bad.This is a machine that cleans out all your pipes and radiators.

Glen.
October 2009

I think we may have a problem with our feed and expansion tank as it is very dirty. I don't think it has ever been cleaned. There is a float valve in the tank, but there is a waterline about 2 inches from where the water starts. Is this normal? The overflow pipe is out of the water. Maybe the tank is blocked with dirt. Would this be the cause of the upstairs radiators not getting hot? Thank you for all your help

Tammi
October 2009

how many rads u using on the system try shutting down rad valves downstairs forcing heat to push upstairs if this works then only open downstairs rads on lockshield end open about 2 turns this will balance the system better dont close all radiators

sean
October 2009

Glen, thanks for all your help.....I think we are going to have to get someone in...oh well. Marksirius, thanks too...we have bled all the radiators...

Tammi
October 2009

It may be that there is air in the system and as it is less dense than water, it will remain at the top of the system. You need to bleed the upstairs radiators to allow the air to escape and the water to fill the space. On one side of the radiator at the top you will find a round hole with a square key inside. You will need a special purpose key which can be bought in any B & Q store for pennies. With the heating system off loosen the key on the first radiator and you will hear the air coming out and the sound of the water gurgling as it replaces the volume of air. Close the valve when water comes out. Ensure you have a tea towel handy and while the air is escaping hold the tea towel below so when the water comes out it does not stain your carpet. Now do all the other radiators upstairs. Hope this helps

marksirius
October 2009

Tammi,I'm afraid I'm running out of simple things for you to try.As you can appreciate it's harder to diagnose a problem on the internet than it is actually being in your house.
I suspect from what you have told me that you may have an airlock or a pipe is blocked,you are going to have to get a heating engineer to look at it.It may be something simple.
I would get someone in as soon as you can as from now until christmas the central heating business gets very busy and you may have a problem getting someone in.

Glen
October 2009

yes I checked that the other side was fully anticlockwise. Is there anything else to try? Thank you for your help

Tammi
October 2009

Have you made sure 'both' of the valves are open on each radiator? One side usually has a valve that you can turn off/on and the other called a 'lockshield' is normally smooth and can't be turned.
You need to take off the plastic top from the 'lockshield' and turn the valve anti- clockwise with a pair of pliers or take the knob off the other valve and use that.

Glen
October 2009

ok we tried to switch off all the downstairs radiators,and the only thing that gets warm upstairs is one pipe running into a radiator, but the radiator itself is cold and all the rest are cold. Any other advice? Thanks

Tammi
October 2009

Try turning off some of the radiators that are already getting hot with the radiator valves, clockwise is off.See if that does anything,could be an airlock.

Glen
October 2009

I have made sure that they are on....is the radiator vent where you bleed the radiators? We have bled them all. Is it possible that there are 2 seperate pumps or anything (we have only found 1 pump in the loft that we can see), or a single valve that feeds the upstairs pipes??? Thanks for your reply!

Tammi
October 2009

Have you made sure they are actually turned on? Maybe the previous occupier didn't want them on and so turned them off with the radiator valves.Also open the radiator air vents ,make sure there is water in them.
I have been in the business over 30 years and I was once called out for this very problem,and solved it in 2 minutes

Glen
October 2009