Some Rads not working HELP PLEASE

[g4cox]

Hi,

Some of my rads are not working, information:
I have replaced one rad with new one and T'd off this one to a towel rail in new on-suite (these are not working) also another one in a bedroom has stopped working (this rad has not been touched).
They are not getting hot/warm at all not even the pipe work I have bleed all rads on filling system and since double checked, balanced rads, turned all rads off bar one non working one, checked TRV's (all fine) and still nothing.
I live in a bungalow, I have just also tested for airlock sounded like some air came out and left water pulling through for a while and hot water did eventually come through however as soon as stopped pulling it through it went cold again.

I have a Worcester greenstar boiler pressure is sat just under 2 and isn't moving (apart from when I bleed them).

Can anyone help?? thanks

 

[JeffD]

Is it a drop fed system them ?

 

[Chalked]

What size of pipe did you tee off?

 

[g4cox]

Thanks for quick responses.

JeffD: Sorry new to heating system how do I tell this? All pipe work from boiler goes into loft then drops down other side of the bungalow in the airing cupboard.

Chalked: All pip work is 15mm

 

[JeffD]

How many rads and how much 22 mil in flow and return is there from boiler

 

[Chalked]

There should be hopefully be some air vents in the loft

 

[g4cox]

JeffD: There are 9 Rads however 3 are capped off, 3 don't work and the other 3 work fine.
3 22mm pipes one is gas.

Chalked: Just having a look, am I looking for 22mm pipe with some sort of cap?

 

[Chalked]

Where is your pump situated and is it circulating through the hot water cylinder?

 

[jase158]

1. check air valves in loft are bled, 2.drain down from every drain point, fill up again but ensure that the automatic air valves in loft are shut. if they don't have a screw on then replace them when drained down, finally open air valves and the system will work.

 

[g4cox]

The only thing by the boil is this but i assume this is not the pump?

 

[JeffD]

It looks pressurised system them, is there a gate valve on the cylinder return

 

[g4cox]

This is what I have found in the loft just above where the boiler is
View attachment 14988

 

[jase158]

invalid attachment

 

[g4cox]

There is is one on a 22mm pipe that comes out of the cylinder and there is a 22mm pipe which comes out the floor and has one one then another then goes back into the floor (doesn't go anywhere else) I have not touched any of these whilst doing any of my work.

 

[g4cox]

 

[JeffD]

I can't open it for some reason says invalid, if there is a gate valve on cylinder return I don't think it will be next to the boiler

 

[hammers4spanner]

Looks like cap ends used for air vents?

pictures not that clear

(welcome back jase)

 

[Chalked]

View attachment 14989

there are your two air vents, you will need a radiator air tap key. Make sure the system is turned off first to let the air settle. Then try the boiler. You may need to do this a few times .

 

[Chalked]

Looks like cap ends used for air vents?

pictures not that clear

(welcome back jase)

they will be compression to female with a 1/2 bsp air vent screwed in.

 

[jase158]

that's the air valves, there may be more, use your bleed key to open the top until air comes out!! shouldn't need to drain, also the valve in previous pic, should have a lever on bottom, open this by hand and latch it on to keep it open and if there is a gate valve on cylinder fully open it, then when everything is bled, turn on heating only but turn boiler down to 0, open one rad at a time until all the air comes out, turn off heating and turn on hot water. when you hear all the water come out, open all rads and fire up boiler, once hot water is getting hot, turn heating on and test all rads. By the sounds of it you may have the pump in boiler (depending on type of boiler) you need to have boiler on low for pump to work. when finished leave programmer on auto/timed and shut gate valve back to where it was

 

[jase158]

and the wb nearly all have pump over run, meaning the pump wil run for 3 miutes after temperature has been reached, so keep checking it is running, you should be able to hear it in boiler,

 

[Baloo790]

Just a thought, have you fitted a new trv? Is it bi- directional? Some cheaper and older ones are not. This means water will only run one way through. Long shot but worth a look

 

[Ermintrude]

Couldn't have said more eloquently if I had tried!

 

[g4cox]

jase, you say turn boiler down to 0 how is this done there doesn't seem to be anything on the boiler with these settings?

Ballo, no new TRV's re-used one old one and the other new rad was a towel rail.

 

[Ermintrude]

Turn temp down on boiler to min, to prevent boiler from boiling air / causing damage