3 radiators stay cold (except when others turned off)

One_Of_Shanks

Looking for some help please.

Upstairs 3 of our 5 radiators stay ice cold. Oddly enough these are closest to the boiler which is in the hot press upstairs beside them. (other 2 upstairs rads are scolding hot)

However, if I turn off the downstairs radiators then suddenly the 3 malfunctioning upstairs ones will start to heat, only a bit. They barely reach lukewarm even after maybe 2 hours of this.

But as soon as I turn back on the downstairs rads, the 3 malfunctioning ones upstairs stop working again entirely.

It's an Oil central heating system. And God I am useless with anything like this so should I call out a plumber or is there anything else I can try?

Thanks in advance

BrokenArrows

One_Of_Shanks wrote: »

Looking for some help please.

Upstairs 3 of our 5 radiators stay ice cold. Oddly enough these are closest to the boiler which is in the hot press upstairs beside them. (other 2 upstairs rads are scolding hot)

However, if I turn off the downstairs radiators then suddenly the 3 malfunctioning upstairs ones will start to heat, only a bit. They barely reach lukewarm even after maybe 2 hours of this.

But as soon as I turn back on the downstairs rads, the 3 malfunctioning ones upstairs stop working again entirely.

It's an Oil central heating system. And God I am useless with anything like this so should I call out a plumber or is there anything else I can try?

Thanks in advance

Has it always been that way or is it a new problem?

AlanG

First thing to try is releasing air from the cold rads - get an old towel and slowly release the bleed valve until air starts to come out, wait until water starts coming out and close it, do this for each one. You may require a radiator key which is about €3 from any hardware store.

If that doesn't solve the problem then turn down the flow to the 2 scalding rads. On the side away from the thermostat or usual on off valve turn down the flow (turn clockwise). You may have to pull the cover off the valve and use a pliers to turn the valve - basically turn it fully clockwise then turn it half a turn the other way. see how hot the rad gets and how quickly it gets hot and then adjust it by small turns to get all the rads heating at the same speed. It can take a several days to get the right balance.

You should also make sure this valve has not been turned down too much on the cold rads.

If this makes not difference it may be that the thermostatic valves on the rads have seized after the summer - you can give them a few taps or just hope they fix themselves but you may well end up having to replace them - i have seen this a couple of times in my house.

One_Of_Shanks

BrokenArrows wrote: »

Has it always been that way or is it a new problem?

New problem. They worked fine last Winter.

AlanG wrote: »

First thing to try is releasing air from the cold rads - get an old towel and slowly release the bleed valve until air starts to come out, wait until water starts coming out and close it, do this for each one. You may require a radiator key which is about €3 from any hardware store.

If that doesn't solve the problem then turn down the flow to the 2 scalding rads. On the side away from the thermostat or usual on off valve turn down the flow (turn clockwise). You may have to pull the cover off the valve and use a pliers to turn the valve - basically turn it fully clockwise then turn it half a turn the other way. see how hot the rad gets and how quickly it gets hot and then adjust it by small turns to get all the rads heating at the same speed. It can take a several days to get the right balance.

You should also make sure this valve has not been turned down too much on the cold rads.

If this makes not difference it may be that the thermostatic valves on the rads have seized after the summer - you can give them a few taps or just hope they fix themselves but you may well end up having to replace them - i have seen this a couple of times in my house.

Super, thanks Alan! Yep I should have mentioned that I have already bled all the radiators in the house. Only one with a wee bit of air-lock was out in the sun-room, rest had clear water immediately, no air.

Will try your other advice when I get home this evening and fingers crossed.... Thanks a mill!

Nemeses2050

One_Of_Shanks wrote: »

Looking for some help please.

Upstairs 3 of our 5 radiators stay ice cold. Oddly enough these are closest to the boiler which is in the hot press upstairs beside them. (other 2 upstairs rads are scolding hot)

However, if I turn off the downstairs radiators then suddenly the 3 malfunctioning upstairs ones will start to heat, only a bit. They barely reach lukewarm even after maybe 2 hours of this.

But as soon as I turn back on the downstairs rads, the 3 malfunctioning ones upstairs stop working again entirely.

It's an Oil central heating system. And God I am useless with anything like this so should I call out a plumber or is there anything else I can try?

Thanks in advance

Hello Shank,


I have a sort of similar problem. Few weeks ago my boiler was serviced and one of the Rads upstairs was bled...since then all four Rads upstairs are getting real hot but Three down stairs are barely heating up...After googling Rads not working even after bleeding I came across THIS Video. Most of the commentators are saying it worked for them. I'm gonna try it tonight. May be you can have a look at it too.

Thanks

_Brian

might be worth having the system balanced properly and see how that goes..

One_Of_Shanks

Thanks Nemeses and Brian. Is that balancing thing about turning off the valve on the left of all Rads? The valve that does NOT control temperature?
And do I turn down temp on them all as well, to the bare minimum?
Is that how its done?

Im currently trying AlanG's steps but after 15 mins its still ice cold. Oddly enough the Rads downstairs are the ones that heat fastest. But are furthest from the boiler which is upstairs.
Hoping it might heat in a few more mins but not looking good so far.
Downstairs ones are fairly hot already.

Very frustrating

EDIT: Nah not happening, still ice cold. Ah well, twas worth a shot.

agusta

Do you have a balance valve[ probally a red wheel type valve] on one of the hot pipes on the sides of your copper cylinder. If so close the valve fully ,then reopen 1 1/2 revolutions
The valve on the left hand side of the downstairs rads,remove the cover off the valve. turn the valve clockwise one revolution on each rad.Then check what difference it makes to rads upstairs

One_Of_Shanks

agusta wrote: »

Do you have a balance valve[ probally a red wheel type valve] on one of the hot pipes on the sides of your copper cylinder. If so close the valve fully ,then reopen 1 1/2 revolutions
The valve on the left hand side of the downstairs rads,remove the cover off the valve. turn the valve clockwise one revolution on each rad.Then check what difference it makes to rads upstairs

Thanks mate! I'll try this this evening and report back. Cheers!!

Nemeses2050

One_Of_Shanks wrote: »

Thanks Nemeses and Brian. Is that balancing thing about turning off the valve on the left of all Rads? The valve that does NOT control temperature?
And do I turn down temp on them all as well, to the bare minimum?
Is that how its done?

Im currently trying AlanG's steps but after 15 mins its still ice cold. Oddly enough the Rads downstairs are the ones that heat fastest. But are furthest from the boiler which is upstairs.
Hoping it might heat in a few more mins but not looking good so far.
Downstairs ones are fairly hot already.

Very frustrating

EDIT: Nah not happening, still ice cold. Ah well, twas worth a shot.

Hello Shank,

It worked for me but on a 2nd shot.

I did as described in the video, turned off all the Rads upstairs and left the downstairs ones On, they all heated up nicely so I went in and fully turned On all the Rads upstairs ( In the video he said only do half a turn) noob mistake .

So when the heating switched on again in the night, the ones downstairs were cold again, I repeated the above steps except this time I only half turned on the upstairs ones and hurray woke upto nice cosy home this morning with all Rads working.

One_Of_Shanks

Nemeses2050 wrote: »

Hello Shank,

It worked for me but on a 2nd shot.

I did as described in the video, turned off all the Rads upstairs and left the downstairs ones On, they all heated up nicely so I went in and fully turned On all the Rads upstairs ( In the video he said only do half a turn) noob mistake .

So when the heating switched on again in the night, the ones downstairs were cold again, I repeated the above steps except this time I only half turned on the upstairs ones and hurray woke upto nice cosy home this morning with all Rads working.

Nice one, glad it worked Nemeses!

I'll try that again myself if I'm still in trouble over the weekend.

BrokenArrows

One_Of_Shanks wrote: »

Nice one, glad it worked Nemeses!

I'll try that again myself if I'm still in trouble over the weekend.

I dont think this will work for you.
As you described when you turn off all the downstairs radiators upstairs still barely gets luke warm.

To me this indicates that the pump is not supplying enough water pressure to heat upstairs properly. When you shut off the 3 radiators downstairs it increases the pressure a little which allows a small amount of water to flow upstairs.

I think you need to look at your pump. Is there a dial showing the water pressure. Should be around 1.5 bar for the water pressure in the pipes. Im not sure about how to check the pressure output by the pump to circulate the water.

One_Of_Shanks

BrokenArrows wrote: »

I dont think this will work for you.
As you described when you turn off all the downstairs radiators upstairs still barely gets luke warm.

To me this indicates that the pump is not supplying enough water pressure to heat upstairs properly. When you shut off the 3 radiators downstairs it increases the pressure a little which allows a small amount of water to flow upstairs.

I think you need to look at your pump. Is there a dial showing the water pressure. Should be around 1.5 bar for the water pressure in the pipes. Im not sure about how to check the pressure output by the pump to circulate the water.

Thanks. Where would I find the pump? I dont recall seeing one. The water pressure gauge next to the boiler says 1.5
I checked it a few times lately after all this started and it basicallyalways stays around 1.5 or 1.6

Also, one of the rads in particular upstairs beside boiler was so hot you could barely touch it. I since turned it down but it was roasting. So if its the pump why did that one get so hot but other ones in nearby rooms ice cold?

God Im crap at this stuff

One_Of_Shanks

Thanks everyone for all your help. Its much appreciated.

One of the "problem" rads is now scolding hot. Though I still have to turn back on the other rads yet.

But even the other day when I had the others off for hours it only got luke warm, but now its literally scolding.

So that surely has to be a good sign.

Going to turn on the other rads again now and fingers crossed but I think we're looking good here.

Can't understand the logic behind any of it but suddenly feeling confident here

dok_golf

Then its not the pump. You need to balance the system. Close the lockshield valve on all 3 problem rads. Open the valve on the first one a half turn. If it heats up, do the same on the 2nd and so on. If there is no heat, then open them in sequence another half turn and so on until you get all 3 right. You may find the one heats up more than the other 2, at which point turn the valve back a quarter turn on the hot rad . The end result should be that the heat is balanced in all 3 rads

One_Of_Shanks

dok_golf wrote: »

Then its not the pump. You need to balance the system. Close the lockshield valve on all 3 problem rads. Open the valve on the first one a half turn. If it heats up, do the same on the 2nd and so on. If there is no heat, then open them in sequence another half turn and so on until you get all 3 right. You may find the one heats up more than the other 2, at which point turn the valve back a quarter turn on the hot rad . The end result should be that the heat is balanced in all 3 rads

Cheers fella! Yeah I'll balance it over weekend. Some are still hotter than others alright but just grateful for now that there are no ice cold or luke-warm rads anymore.

Still baffled as to why it suddenly kicked back into life when I had done the same thing last week and aside from temporarily becoming luke warm it hadnt worked.

But hey, happy as fook now. Kids room is nice and toasty and that was my main aim.

Thanks again everyone for all the help along the way, fair play!