Problem with an S-PLAN motorised valve.

[MikeSharp01]

Friends of ours are having problems with their hot water over a period and they have had a plumber look at the problem, who said it was an issue for an electrician, they don't want to call a plumber today for obvious reasons, and so I said I would pop round and have a look at it. Its not a particularly odd one, basically the hot water tank is getting flow through the heating coil despite the call for hot water being off. So I looked at the S-PLAN valves and and noticed that that their electrician, under instruction from the plumber, had already fitted a new head to the hot water valve (A Honeywell 272848 normally closed valve) but they left the new valve body on the floor!

 

Cutting a long story short I took the motorised head off the valve and forced the valve shut with a spanner and it looks like it still lets by so my question is: Do these valves let by when they are forcibly closed - I thought they were rubber balls so pushing past the end stop of the motor, without the motor attached, should close it but it does not appear to. So my diagnosis is that the valve body will need to be replaced but I wanted confirmation that forcing the valve shut can still result in flow getting through - has the ball fallen apart for instance?

 

[ProDave]

You should be able to shut it off with little force.  Does it turn freely with the head off?  It will only turn roughly 90 degrees, and as you say the closed position should be a soft stop where the flow is plugged.

 

If the plumber could not check that and passed the buck to an electrician, time to get another plumber.

 

Is the valve seemingly opening and closing correctly with the head on?  Can you see it rotating?

[MikeSharp01]

 

 

40 minutes ago, ProDave said:

Is the valve seemingly opening and closing correctly with the head on?  Can you see it rotating?

The valve moves freely and you do feel a certain squishiness when you close it with a spanner. I have not managed to power up the head because I didn't want to disturb the settings, the hot water is set off. I can play a bit now as the heating has warmed up their house. There does not seem to be any other way for the water to flow so the valve must be letting by. I did notice that with the head on that the the manual lever di not seem to engage until almost the end of its travel but the head does drop onto the valve in the correct position.

 

 

 

[ProDave]

These actuators are a pain to test as they don't work with the actuator off the valve, the mechanism relies on being on the spindle of the valve and just won't work properly if you try and energise it off the valve.

 

I always find it is difficult to tell if water is flowing as you don't have a flow meter, you can only go by is the water hot both sides of the pipe etc, so when it closes you have a while to wait to see if the pipes cool down or not to confirm if it has closed and water has stopped passing.

 

 

[MikeSharp01]

3 minutes ago, ProDave said:

I always find it is difficult to tell if water is flowing as you don't have a flow meter, you can only go by is the water hot both sides of the pipe etc, so when it closes you have a while to wait to see if the pipes cool down or not to confirm if it has closed and water has stopped passing.

Yes I forced it closed with a spanner and wedged it, left it for a period of 30 minutes no change in temperature.