Problem with flow to upstairs radiators

[hobbedy]

Hi everyone, I've got a query!

I recently decided to do a mains flush on my central heating system (pumped system, worcester bosch boiler) as per the excellent instructions on this site.

It all went fine downstairs with mucky water then finally clean from each rad, but upstairs was a different story. Basically I couldn't get any flow down the flow pipe to the drain point from the upstairs radiators, and I eventually realised that something (other than a possible airlock) was blocking the flow back down the flow pipe from upstairs.

On uncovering a removable tile in the room with the boiler I found the flow and return pipes to the upstairs radiators, and the flow pipe has a strange looking bulky valve fitted inline, with a screw adjustment (which is actually leaking a tiny bit).

I looked through posts on here to see if I could ascertain what it was, and it seems that it could be a one way valve, but it also seems one way valves are only used on pumped heating with gravity hot water to prevent the rads warming up when the hot water is on(?) but I'm sure our heating and hot water are both pumped (I'm reasonably sure I can hear the pump start up for both heating and hot water demand).

Is it possible the valve is left over from a previous install (I'm not sure of the system history only that the current boiler dates from 1994)?

Anyway getting to the point, I really want to flush the upstairs rads and now I've found the valve to be leaking I'm wondering if I can simply remove it altogether to facilitate this. Can anyone think of a reason for it to be there?

Just FYI, there's 10 radiators in total, 5 upstairs and 5 down, and when operational the entire system works fine.

cheers

 

[Bahco]

If you have a fully pumped system with 3 port valve, then the anti gravity valve will be defunct and can be removed.

 

[kevindgas]

can't be sure without a picture it could be an isolation valve but it could also be a single check valve to stop reverse flow when in hot water only mode

a drawing or photo would help

 

[gas4you]

Firstly you must be attempting to flush the upstairs against the flow direction of the valve, as you state the ch works fine.

Usually these are indeed just left over from a previous old gravity system and can just be cut out and the pipe joined, especially if it is leaking.

Very occasionally and rarely one may have been installed on a fully pumped system to again prevent gravity circulation to upstairs rads, rather than finding the original cause to the problem.

 

[hobbedy]

Hi,

thanks everyone for the super quick replies.

Firstly you must be attempting to flush the upstairs against the flow direction of the valve, as you state the ch works fine.

Yeah that's what I figured after thinking about it for a while. I just had a look in the attic as I remembered seeing some old pipe work in there, and it seems there's some pipework from a previous install (maybe from a water tank) and also 28mm piping (empty and cut off at one end) running next to the flow and return pipes to the upstairs rads.

I just took a pic of the valve, here it is:

As the valve is leaking (albeit very slightly) I'm going to need to either clean it up or replace it if it's actually necessary, so what reasons would there be for leaving it in, or is the concensus that I can just get rid of it and repipe?

thanks once again!

 

[gas4you]

I personally would just get rid of it

 

[hobbedy]

I'm not sure (even from consulting the boiler manual) whether I have a 3 port valve or not, the boiler model is the Worcester 350 Combi.

 

[gas4you]

In that case then, no. Just remove the dumball valve.

 

[hobbedy]

Cheers Dave, and thanks to everyone for their help, will do!