Radiators upstairs not working

scaffrey82

Hi there

Some of the radiators upstairs in our 3 bed mid terrace are not coming on. I thought it was a balancing issue, so I switched all the rads off and introduced heat to them one by one. All came on and were piping hot! We switched the heating off that night and the next day when heating was set to come on, all came on bar 3 bedroom ones. There is no sludge etc in them as we had them flushed last year (btw it was a brand new house, only 5 years old so didn't even need that done, but thought it might be a factor) ... Also bled the radiators so no air locks. The fact all came on when I balanced the system means they all work, no valve issues, but can't understand why the heat wont flow to them now?

At my witts end with a baby on the way in less than 7 weeks!!

Any advice?

Billy Bunting

It doesnt sound to me like you balanced the system, you just turned them off and on :P you need to reduce the flow on the lockshield side, thats the valve that does nothing, its for balancing the system, if they are open to much the pump will find it easier to pump to them rather than the others.

scaffrey82

Billy Bunting wrote: »

It doesnt sound to me like you balanced the system, you just turned them off and on :P you need to reduce the flow on the lockshield side, thats the valve that does nothing, its for balancing the system, if they are open to much the pump will find it easier to pump to them rather than the others.

Oh ok, I didn't realise one side was for balancing. The white nobs covering the valves are the same in appearance on my system, and they are turned on to the max on all radiators ... so how do I know which one to turn down on the working radiators to allow flow to the non working ones?

heinbloed

A lot can be said about the hydraulic adjustment, the 'balancing' of a wet system...

In principle the outlet temperature of all radiators have to match.
Basically all of the (thermostatic) inlet valves have to be opened and the outlet valves as well.
Then the CH system has to run for a while, half an hour or so.
Then the temperature at the outlet valves is meassured and recorded.
And then the hottest outlets are closed bit for bit. Until the recorded temperature is level with all other outlets.

If this is done we have achieved a thermal balance.

Now we can adjust the boiler temperature. As low as possible with condensing boilers !

Plain story.

There are also automatic pumps and (thermostatic) valves available which are self balancing/adjusting.

What scaffrey82 tried first is called flushing, not balancing.

Here a little sketch:

http://www.grundfos.com/service-support/encyclopedia-search/balancing.html

Billy Bunting

scaffrey82 wrote: »

Oh ok, I didn't realise one side was for balancing. The white nobs covering the valves are the same in appearance on my system, and they are turned on to the max on all radiators ... so how do I know which one to turn down on the working radiators to allow flow to the non working ones?

To put it as simply as possible :rolleyes:

Use all the right hand side as your lockshield valve, turn them all off other than the one furthest away, turn on the heat, then just crack open a half turn the lockshields on the other rads, do they heat ? the ones that dont then crack open their valve another half turn, do this until rads all heat, hopefully that will get you out of trouble until you next have the service man out, you can then get him to do it.

http://www.youtube.com/watch?v=QUWbxccVDpc

JohnnyCrash

Maybe its a sealed system and the pressure is low???

gdavis

if u have not got 2 way rad valves on rads,u may have to check which side of each rad is flow and which is return.if u turn boiler on from cold and go to each rad and see which pipe gets hot first,that will be ur flow,open all flows fully and then balance ur returns and dont forget about the coil in cylinder

scaffrey82

Hi Guys ... So I turned off all rads, incl the pressure valve and turned on each one at a time, ensuring to note which side was the pressure valve. First rad i started on was main bedroom at front of house, and it heated, but as I turned on the others in the house, the rad in main bedroom became cold, despite me leaving that pressure valve open to the fullest and the others only twisted a notch. All rads heating now bar the one in main bedroom. Any ideas? It doesn't need to be flushed and is not airlocked as it was boiling before I switched on others, just seems the heat is not reaching it once others are on? I even switched rads off down stairs and just left the rads on upstairs to see if that made a difference and it didn't... Got a gas bill of €400 in the door and im raging as its not like the house is even hot to justify those bills!

.243

scaffrey82 wrote: »

Hi Guys ... So I turned off all rads, incl the pressure valve and turned on each one at a time, ensuring to note which side was the pressure valve. First rad i started on was main bedroom at front of house, and it heated, but as I turned on the others in the house, the rad in main bedroom became cold, despite me leaving that pressure valve open to the fullest and the others only twisted a notch. All rads heating now bar the one in main bedroom. Any ideas? It doesn't need to be flushed and is not airlocked as it was boiling before I switched on others, just seems the heat is not reaching it once others are on? I even switched rads off down stairs and just left the rads on upstairs to see if that made a difference and it didn't... Got a gas bill of €400 in the door and im raging as its not like the house is even hot to justify those bills!

when you say you twisted it a "notch" how much of a turn ?,
you nearly have it sorted by what billy explained to you,that rad could be the last one to get heat so try turning down the balance side of all the othe rads in the house a small bit and it that dont work turn off all the rads in the house except the problem rad but open both sides fully and turn on the heat for a while to give it a good "roasting",
then when its hot re set up the balance and leave it on and turn on the rads one by one,
sometimes rads can get lazy even though the system is correctly balanced but water will go where it wants to go no matter where you allow it to

heinbloed

The OP wrote:

...First rad i started on was main bedroom at front of house, and it heated, but as I turned on the others in the house, the rad in main bedroom became cold, despite me leaving that pressure valve open to the fullest and the others only twisted a notch....

The situation can't be described any better: this CH system is not hydraulically adjusted ("balanced").

Get a thermometer, use it at the outlet of the radiators and adjust the flow rates until they all show the same temperature.

There is no other way. Unless you get a heating engineer who is capeable to do the theoretical calculations and adjusts the flow rates accordingly.

scaffrey82

Thanks for replies... so I guess a little more patience and a few more adjustments, repeating the same process until rad stays hot. Original problem included 2 back bedroom rads also and they are fine now, so ill try again until main bedroom stays hot. Baby coming in 5 weeks (please god) and will be in that room with us so I really need to get it sorted ... fingers crossed!

scaffrey82

I don't want to hold my breath just in case, but I balanced the system again last night and left it on for 4/5 hours, all rads boiling. Had it set to come on at 8 this morning and .... all rads boiling!! So fingers crossed this is it and no more hiccups. Thanks loads n loads for the advice and your patience with me. Gona give the 'other half' a lesson on balancing so that he can do it if ever needs to be done again. :D:D:D Very happy girlie here!!

gdavis

what size is boiler and how many rads is it doing?size of rads?

scaffrey82

gdavis wrote: »

what size is boiler and how many rads is it doing?size of rads?

Seems to be working now gdavis... but 4 rads down stairs and 6 upstairs