This is my first posting, so hopefully I have done this properly. I'm sorry it is so long winded.
For quite a while, the tap hot water temperature has been scalding, when the central heating has been running. During the summer, when the heating has been turned off, the hot water runs correctly at the temperature set by the thermostat on the hot water tank.
Having taken off the actuator, I can see that the three port valve is leaking slightly, so have assumed that the valve has seized in the mid position, which would explain why the water temperature is so hot when the heating is on, and also explains why the hot water doesn't need to be programmed in the winter, to still get scalding hot water.
Just to double check that the problem was the faulty valve, rather than the wiring, I wired up the new actuator/valve, with the old actuator still wired up. (The new valve/actuator sitting on the table, and the existing actuator lifted off the existing valve which was still plumbed in).
The problem I have found is that when the hot water AND the heating are running, the new valve continually hunts from being in the mid position, to closing off the hot water, and then back to mid position again. The valve moves from mid position back to mid position every 20 seconds or so. As soon as the water is up to temperature, the valve moves to the left, and closes off the hot water completely. As soon as the water temperature in the tank goes down, and calls for hot water, back goes the valve hunting motion again. It works perfectly when just on hot water only, or just heating only, so it is only when both are running. (While the new actuator/valve was hunting, the existing actuator did not hunt, even though they were both wired up at the same time).
Does anyone know why the new valve/actuator is hunting please ?
I could just programme the hot water to run at a different time to the heating, to stop the valve moving sixty times while the water heats up for 20 minutes every day, but I would be interested to know why it is happening please.
The existing motorised mid position valve is a Danfoss H Series HSV3/HSA3. The new valve is a Honeywell V4073A motorised mid position valve.
Thank you.
For quite a while, the tap hot water temperature has been scalding, when the central heating has been running. During the summer, when the heating has been turned off, the hot water runs correctly at the temperature set by the thermostat on the hot water tank.
Having taken off the actuator, I can see that the three port valve is leaking slightly, so have assumed that the valve has seized in the mid position, which would explain why the water temperature is so hot when the heating is on, and also explains why the hot water doesn't need to be programmed in the winter, to still get scalding hot water.
Just to double check that the problem was the faulty valve, rather than the wiring, I wired up the new actuator/valve, with the old actuator still wired up. (The new valve/actuator sitting on the table, and the existing actuator lifted off the existing valve which was still plumbed in).
The problem I have found is that when the hot water AND the heating are running, the new valve continually hunts from being in the mid position, to closing off the hot water, and then back to mid position again. The valve moves from mid position back to mid position every 20 seconds or so. As soon as the water is up to temperature, the valve moves to the left, and closes off the hot water completely. As soon as the water temperature in the tank goes down, and calls for hot water, back goes the valve hunting motion again. It works perfectly when just on hot water only, or just heating only, so it is only when both are running. (While the new actuator/valve was hunting, the existing actuator did not hunt, even though they were both wired up at the same time).
Does anyone know why the new valve/actuator is hunting please ?
I could just programme the hot water to run at a different time to the heating, to stop the valve moving sixty times while the water heats up for 20 minutes every day, but I would be interested to know why it is happening please.
The existing motorised mid position valve is a Danfoss H Series HSV3/HSA3. The new valve is a Honeywell V4073A motorised mid position valve.
Thank you.
