Cyltrol valve

[JohnD]

My mother has one (gravity feed to HWC). It was set a bit cool so I tried to turn it, it was stuck and I broke the plastic knob on the splined shaft and turned it with pliers. I think I have set it too hot now

It looks like it is only supposed to turn about 180 degrees, with a stop on it. Does anyone know the correct way to set it?

Also, is it possible to get splined knobs? the original one was about as flimsy as the cap on a lockshield, so I could do with something more solid as it is still quite stiff.

 

[chrishutt]

Cyltrol valves go back to the 1970s! I'd be surprised if you can still get spares, but it might be worth a Google.

The blue knobs had two stops so that the knob could be set at the correct setting. The valve responds to the return temperature of the water which will be more or less the same as the stored water at a low point on the cylinder, so I'd aim for it to close down at about 55°C. I'd be doubtful of the accuracy of the wax capsule after so many years.

How about upgrading the whole system to fully pumped, or at least fitting a motorised valve to the return pipe with an interlock to the boiler. That will operate more efficiently than a Cyltrol, which doesn't stop the boiler cycling.

Later....What do you know, they still make the thing, so spares should be available. I still think it's way past it's sell-by date.

 

[JohnD]

Cyltrol valves go back to the 1970s!

my old mum goes back a lot further than that!

I think I'll try screwing it down, then slowly slackening it off until it opens, and feel the return pipe temperature until it seems about right...

Maybe I can find a RF cylinder stat to prevent the boiler cycling when the cyl is hot... should be less trouble and expense than converting to fully pumped. The route between boiler and cylinder is quite long, and taking up all that carpet and floorboards would be tedious.

 

[chrishutt]

.. should be less trouble and expense than converting to fully pumped. The route between boiler and cylinder is quite long, and taking up all that carpet and floorboards would be tedious.

Conversion to fully pumped doesn't involve changing the pipework. You pump through the same flow and return pipes. You'll get faster heat-up of the cylinder and so shorter boiler firing times.

 

[JohnD]

I meant, taking up the floor for the cylinder stat wiring

could I put a new pump on the DHW supply instead of a 3-way?

edited: now I think of it, I don't really want to do much. I don't live nearby and wouldn't want to take on a job that would take me more than half a day

 

[Agile]

The Cytrol have a wide adjustment range but that is limited by stops on the knob.

Its just a matter of trial and error to get the right setting.

Many are now old and seized up but still regulating.

Quite an expensive bit at about £85 but people still buy them for replacements.

Not very efficient when the CH is off.

Tony

 

[JohnD]

the boiler's a Potterton Profile 100e, lots of iron in it. I've been insulating the pipes recently. does that make any difference?

 

[Agile]

Its always a good idea to insulate pipes!

Tony