Radiator Help!! pipe hot, radiator not

[Andrew Massey]

Hi hoping someone may be able to guve me some pointers.
Downstairs radiator lockshield pipe is hot, radiator not at all and temp valve end and pipe not either.

I have taken radiator off and flushed, checked thermostat valve pin is going up and down and played with lockshield valve. Tried turning all rads off in house and boiler in full but still no luck, just makes the pipe feedin it hotter!
The heat is on the pipe, the valve and the ball shape (see pic) part of the bottom of the radiator

 

[Riley]

If you remove the rad do you get flow out of both rad valves

 

[Andrew Massey]

Sorry to sound completely thick, would the heating need to be on to know this when the radis off ?

 

[Andrew Massey]

I hav just tried all rads off apart from trouble rad and put boiler to max and there is some slight heat going through it but not enough to heat a room

 

[Riley]

You should get flow if it’s on or off. However mind if it’s hot. It would imply to me you have a flow problem and we need to ascertain if that’s a radiator or a valve/pipework problem

 

[New Gas Engineer]

I would be tempted to take the rad off and put an empty ice cream tub or similar container beneath the lockshield and open it slightly.

Regardless of whether the heating is on or off you should get a good flow of water coming out of the lockshield. That implies the fault is elsewhere.

If you get a very slow drip/sputtering, it means you have a blocked lockshield. Best solution would be to replace it.

 

[AMGasServices]

It appears to be microbore pipe could be a restriction on the return or flow side.

 

[Andrew Massey]

Thanks for the pointers. Think i will jave to take rad of at the weekend.
Regarding the microbore, the house was built in 2003, i read sonething saying it was popular in 70’s ?

 

[JCplumb]

Thanks for the pointers. Think i will jave to take rad of at the weekend.
Regarding the microbore, the house was built in 2003, i read sonething saying it was popular in 70’s ?

Yeah it was popular in the 70s and up to present day unfortunately.
It's more prone to blocking due to the smaller diameter, a lot of installers use the crimping type reducers into 15mm valves which are awful if they ever leak, the amount of heat they can deliver is lower etc. Lots of reasons why I prefer good old 15mm from 22mm f/r.
My guess is one of the pipes is bunged up and you'll probably be able to clear it into a bucket once you remove the rad.