Faulty 3 Port Valve (Mid Position) or not!?

[ISM]

I just want to run this by you pro's out there, can't say I am a pro yet - but getting there!!.😕😕😀

This is the scenario:

When the heating and h/water, the water dosent always heat up so to solve this problem the customer puts them on the timer at different times. This worked most of the time but on occasions the water still didnt heat up. Also when the water is only on the radiators often get hot.

I have checked the Programmer - is okay
I have checked the Cylinder stat - is okay
I have checked the Room Stat - is okay

To be fair everything worked fine when I got there (the customer commented it is intermittant), But my experience is telling me that the power head needs replacing on the Motorized valve, the head gear is also fine.

Any feedback would be most appreciated, cheers

Ross

 

[doitmyself]

Download the Wiring Guide from Honeywell :: Register.

It contains very good fault finding info.

You have to register before you can access or download anything.

 

[LIFES A GAS]

After removing the head, can you move the spindle with your fingers? If you can’t then the valve probably sticking, you can try and free it up by working in some oil. It is unusual for a 3 port valve not to operate on hot water unless it is sticking, the springs in the actuator should pull the valve back to the HW position when the power is turned off or you select HW only with the cylinder stat in demand. Your other problem with the rads getting hot when you select HW only can be for the same reason or you have a buildup of sediment in the valve preventing the valve from seating and therefore letting by (like a dripping tap) another reason could be the rubber ball has swollen or is damaged. Hope this helps,
Martin.

 

[fuzzy]

sounds like a mechanical side of the 3 port is faulty as opposed to the wiring. You could mess about for ages, just change the full valve and re wire correctly,