Airing cupboard gate valves

[Kton2002]

Hi all,

So, will be brief! Moved into house (6 years old), decided upon some advice to turn gate valves off and on again then back 1/4 turn to keep free. Most turned ok, one was stiff but now fine. However my question is I can't remember if one was not fully open or not! I think at least one maybe even 2 were not fully open. I think this may be to do with balancing hot water and heating when both are on. Pic attached! Any help gratefully received. Thanks again

 

[Kton2002]

 

[rjm2k]

It looks like you have an auto bypass so it's probably not that one, there are 5 gate valves in the photo, which ones do you mean?

 

[Hugh Jaleak]

Heating has an automatic bypass valve fitted looking at the pic, should have been set by the installer so shouldnt be touched. The valve at bottom on the cylinder return may need shutting off half way(ish), to restrict the flow through the cylinder. Should HW and CH be on at the same time it ensures a flow through the heating circuit rather than the cylinder robbing the lions share of the flow from the boiler, (until cylinder temp is satisfied and the motorised valve shuts off.) The rest are just for isolation if the various supplies need shutting down.

 

[Jackrae]

Can only say that, in my humble opinion, turning ON then OFF or OFF then ON to "keep valves free" is absolute cods-wollops. What hydraulic problems could be caused during the period when valves are in the incorrect position. Certainly the valve should never be screwed tight to its limit and the advice of turning back say a 1/4 turn from the fully Open or Closed position is good sense. As you have now established, you have moved the valves and are no longer confident in which position they should be - that's where labels on each and every valve come in handy. The label should define its function and state the "normal" position of the valve ("normal" in this context being the position the valve is in when the system is in "normal" operation)
Now sits back and waits for flak

 

[45yearsagasman]

Well you asked for it
I recall dozens of gate valves that were never touched for many years, and I was the poor s0d that had to change them when the shaft sheared inside when trying to turn them. If only they'd have been turned a few times to prevent this.

 

[Kton2002]

Thanks Hugh and all. I believe it was the valve at the bottom of cylinder that was only half on, so have put that to half way. Everything seems to be working fine. I think in future ill leave well alone, despite reading that turning then twice a year is good preventative maintenance!

 

[Hugh Jaleak]

Personal opinion is to turn valves on/off now and again, in a hard water area like here it may help prevent the innards of the valve scaling up to the point the valve no longer works.

Not many people do though, resultingly invariably the entire system needs to be drained before any work can be carried out...

If you do move gate valves, it's wise to note the position there were in and leave them in approximately the same position afterwards.