Clonking New motorized zone valve (2 way)

[OllyJC]

I recently posted on the forum a query regarding hot water getting too hot and eventually resolved this by fitting a new zone valve, as the old one was apparently stuck open.

Whilst this has fixed the problem with overheating the water, there is another problem since fitting the new valve. When the valve opens or closes, there is lout 'wirrr' then a 'clonk!'. When watching the valve and surrounding pipework while it does this, the whole lot shudders at it clonks.

I thought that the new valve may have been wired incorrectly, but I've tried switching the grey and orange wires and this seems to make no difference.

If the new valve is not wired incorrectly, is it possible that it is the wrong type of valve? (It is a Honneywell and looks the same as the old one)

 

[namsag]

Did you put it in with the flow in the right direction

 

[OllyJC]

I put it in the same way up as the old one - but admit, I didn't check the arrow on the side. How do I know if it's the right way - the pipe comes from the bottom of the HW cylinder into the bottom of the valve?

 

[namsag]

The valve body will have A and B marked on it(possibly an arrow) instuction leaflet will tell you what way the flow should pass through it

 

[OllyJC]

the arrow is pointing up - away from the cylinder, towards the pump

 

[D_Hailsham]

the arrow is pointing up - away from the cylinder, towards the pump

Then it is the wrong way round. The motor is trying to close the valve against the pump pressure, which is trying to open the valve, so you are getting vibration. If you turn the valve round, the pump pressure will help to keep the valve closed.

For info. Some experts reckon that it's more efficient to have the flow going into the lower connection of the cylinder and the return coming out of the higher connection. This is what you have.

 

[twgas]

assuming the pump is on the flow, you've got the valve the wrong way round, there should be an arrow on the pump as well, I suspect this is pointing towards the valve.

 

[OllyJC]

Seems like I'm going to have to drain down the system and switch the valve around. I'll let you know if this works. Thanks for the advice.