New rad off boiler F/R not working

[Monkey]

Hi all, I'm looking for a little advice please.

I've just installed a new rad directly off my boiler f/r, but I'm unable to get any heat through the radiator.

It's an old back boiler, with 22mm pipes off the boiler, and microbore to the rads. I used 22mm to 15mm reduced tees off the boiler f/r to the new rad with a TRV on the flow side (though I believe it's a bi-directional TRV anyway).

If I turn off each side independently and bleed the radiator, I get continuous flow, and hot water starts entering the rad (whilst bleeding). So both sides seem to be working OK, but when both open I'm just not getting any flow. When normally on, the return pipe gets hot, but nothing else.

I was thinking an air-lock, but not really sure.

I was really hoping to avoid having to hook up to the pump as it is not in a great location for this extra rad. I had a plumber quote for the job, who suggested hooking up to the boiler f/r should work.

Any ideas? Thanks in advance.

 

[sammathias]

Is your system fully pumped or isit pumped heating gravity hot water?? How many pipes come off back boiler??
Could be an airlock but more likely to be piped up wrong?

https://www.google.co.uk/url?sa=t&s...ICz8QFggmMAA&usg=AOvVaw0wmmP4W5aD8Qn5zldP3B8h

Page 15 and 16 may help you out.

 

[Monkey]

Thanks for the link, it's actually a Glowworm back boiler.

Fully pumped. 3 x 22mm pipes out the side of the chimney breast, 1 gas, then return and feed.

Even though it's a pumped system, I was told that feeding one rad straight off the boiler (before the pump) f/r should be fine (although obviously it will come on with the hot water, but can be turned off manually when not needed).

 

[sammathias]

turn heating on and close all trvs on other rads apart from the new rad and see if it pulls hot through the rad?

 

[sammathias]

Any pictures of the connections?

 

[ShaunCorbs]

Sounds like your trying to do the rad in gravity won't work stick it after the pump

 

[sammathias]

He said its fully pumped...

 

[Monkey]

Thanks everyone. I decided to fully drain down and refill. All seems to be working now. Thanks again.

 

[ShaunCorbs]

He said its fully pumped...

But he's done it before any port valves eg comes on any time

If the pump doesn't come on when you want the rad on there's your problem

 

[sammathias]

The rad will come on when you turn hot water or heating on....so will the pump.

 

[Last Plumber]

It sounds like it’s piped wrong.

 

[Monkey]

It sounds like it’s piped wrong.

Quite possibly, but as everything is now working, the Mrs is happy, and so job done for now.

When I next get access to the pump area I'll re-route it properly.