Rad not heating up!

[2020c]

I have 16 rads in my house. Got work done a few years ago and moved the rad with some plastic pipe. The plastic pipe was connected where the rad was, and instead of drilling holes through the joist. The pipes where brought over the joist in the void area then back into the same room on the same side, same wall only now on the left side instead of right.

To this day, the rad has never heated up. I was thinking it was maybe an air lock. Tonight I connected a flexi hose to the rad valve on one side. Opened it, let the water run through it for a few mins to see if this pipe was air locked. Water was roasting. I did this again in the other side rad valve. Roasting the water was like the other side.

Put rad back on, opened the air bleed valve. Let the water out. Rad mildly heated up then went cold!

I'm baffled at what's going on. All that was done was the same size pipe connected to where old location was. Brought to new location with lagging. New rad valves and now theres no heat at all to the rad.

 

[terryplumb]

Turn off every other rad by its TRV,see if the cold rad heats fully. If it does you need to balance the system

 

[2020c]

Turn off every other rad by its TRV,see if the cold rad heats fully. If it does you need to balance the system

I tried balancing it before about a year ago and wouldn't heat up. I'll try again. They are trvs, they are normal rad valves.

 

[terryplumb]

If no TRV use the wheel head valve ,leave their lockshields alone.

 

[2020c]

If no TRV use the wheel head valve ,leave their lockshields alone.

What ya mean. What's difference between lockshield and wheelhead Valve.

Is the wheel head the on and off and lockshield is one that's left alone

 

[terryplumb]

Is the wheel head the on and off and lockshield is one that's left alone

Yes. A lockshield typically would have a domed cap, which has to be removed to alter the valve with a spanner.
Wheel head valve has a handle / knob that you turn by hand , and often + or - on its top.

 

[2020c]

Yes. A lockshield typically would have a domed cap, which has to be removed to alter the valve with a spanner.
Wheel head valve has a handle / knob that you turn by hand , and often + or - on its top.

All wheel valves off. Still no heat to the rad

 

[terryplumb]

Did the original rad work ok before pipes were moved ?
It would appear to be incorrectly plumbed in ,both pipes connected to flow .
Is it a standard panel radiator ?

 

[2020c]

Did the original rad work ok before pipes were moved ?
It would appear to be incorrectly plumbed in ,both pipes connected to flow .
Is it a standard panel radiator ?

This room has never really been used untill now. Had issues with it before but got plumber to look at it , got it working but then room never used. Had the work done few years later but never turned rad on.

Yeah standard panel rad.

I can't see the both pipes being plumbed into same pipe.

I'm at it now, have the air valve open and it's very very slow the air coming from the rad.

 

[2020c]

 

[2020c]

I was there when it was moved it from one side of room to other. Push fitting 90s where rad valves where. 1/2 inch plastic to new location with push fit 90s under floor then up to rad valves.


Sitting here listening to the air coming out and it's struggling. All rads off. Heating on . Pump working.

 

[terryplumb]

Is system pressure good ,around 1.5 bar ?
Sometimes the air bleed valve can get partially blocked, it's a tiny hole on the inside.
If ,when you removed the rad, water flowed freely from both valves for more than a full minute ,that rules out a blockage in the pipes. That only really leaves a blockage in the rad ,or incorrect connection to both flow and return pipes.

 

[2020c]

Is system pressure good ,around 1.5 bar ?
Sometimes the air bleed valve can get partially blocked, it's a tiny hole on the inside.
If ,when you removed the rad, water flowed freely from both valves for more than a full minute ,that rules out a blockage in the pipes. That only really leaves a blockage in the rad ,or incorrect connection to both flow and return pipes.

When I removed the rad, I emptied the water down the toilet. Water flowed out if it and all blackish color.

I attached the flexi to both pipes one at a time and let the hot water run out of it for awhile. Maybe a min or more each side.

I have now the screw bleed valve nearly fully out and no air is coming out at all.

 

[old duffer]

Radiators need a pressure differential across them to instigate flow. Have you checked the pressure on flow/return...?
Next is circuit flow i.e. does the water want to flow into the rad or continue to bypass it? Close couple Tees, water brake, pipes sizes..all effect it
Next is air lock or air pressure. I have a situation currently where I have just refilled for the new season. The boiler flow is 1bar and at the ned of the circuit (rads not yet working) its 2bar. It takes a while to get the air out BTW

 

[2020c]

Radiators need a pressure differential across them to instigate flow. Have you checked the pressure on flow/return...?
Next is circuit flow i.e. does the water want to flow into the rad or continue to bypass it? Close couple Tees, water brake, pipes sizes..all effect it
Next is air lock or air pressure. I have a situation currently where I have just refilled for the new season. The boiler flow is 1bar and at the ned of the circuit (rads not yet working) its 2bar. It takes a while to get the air out BTW

Haven't checked pressure on flow /return. How can I do this? Is it flow/return the full system or just where rad is.


I don't understand you when you say does the water want to flow into the rad. Tees, water brake etc .. what I can say tho. These pipes where extended from an already long 1/2 inch pipe. The 3/4 pipe it branches off is on other side of house which is about 7m then I attached an elbow an extended the pipe in 1/2 in again and if I remember right, I've another elbow under the floor up to the Valve in 1/2 again.

I was thinking it might be air locked. But how come the hot water flowed out if the pipe when I had the flexi on.



Just now, I took the screw fully out, nothing was coming out if it then I covered it with my finger then air started rushing out fast then water shot out. I let the water run out of the rad air bleed part till I filled up a kitchen pot. When this was happening, part of the rad was getting warm. Soon as I closed it, the rad got cold again.