Danfoss Randall HPV22 22mm 2 Port Valve replacement

[uyevuye]

Hi All.


I have 2 Danfoss actuators. I believe one of the valve is broken. I have tested the motors / actuators by swapping them around on two different valves.
One of the valves has worked as expected. Other one did not. So I think valve is broken. I have ordered a replacement valve.


( https://m.media-amazon.com/images/I/51en+tBbI3L._AC_SL1024_.jpg )


Do you think it will be an easy task to replace or should I get a professional?


I have a pressurized heating system with Unvented Cylinder for hot water.


I thought I should follow below procedure.

Turn off the power for the boiler

Turn off mains water

Turn off the tap before Danfoss circulating pump
Turn on drain valve in the ground floor

Open the bleeding valves for all radiators

After water is all run out take motor and broken valve out
Install new one valve and put the motor on

Turn off drain valve

Start to fill system on the pressurized tank
Close the bleeding valves

Turn on the circulating pump

Turn on mains water

Turn on the power for boiler


Do you think I am missing a step?

Thanks

 

[oldbuffer]

1. If its the valve for the unvented hot water cylinder, you should get a G3 qualified engineer to fit it. The valve is part of the cylinder's safety equipment.
2. If its the central heating one, you can do it.
3. With respect to your task list:
3a. Its broadly correct.
3b. You don't need to turn off the pump valve(s).
3c. You only need to drain down to the level of the valve to be changed (or a few cm below it).
3d. Open the radiator bleed points from top down, as you drain, otherwise water from higher ones will come out of the lower ones.
3e. Close all radiator bleed points once drained, then re open them bottom up when refilling.
3f. Circulating pump shouldn't need "turning on". See 3b. above.
3g. You will need to renew the system's inhibitor. If you are confident of no leaks, do it before refilling. Otherwise fill and test, then a very partial drain down and add inhibitor.

 

[uyevuye]

Thanks for your reply. It is central heating one.

If my tasks list is correct only thing I should worry about is installing the valve correctly without leaks or overtightening the olive. BTW should I use teflon tape?

 

[uyevuye]

This is the system. So is it still OK to DIY?
Both white actuators are connected to same port on the controller.

 

[oldbuffer]

1. Yes its OK to DIY.
2. Looks very tight for space to get the old one out and the new one in.
3. I'd have been tempted to replace the entire valve, as its generally not much more than the "wet" part alone. But if you've already got the wet part, that'll be fine.
4. If you can move the spindle (actuator removed) of the old valve by hand, I wouldn't be too sure its the valve at fault, could be the motor and / or actuator.

 

[ianmcd]

If its just the actuator and the valve moves freely enough, just change the actuator, no need to drain anything , jst slide the lever to manual and if it moves aesily you only need to change the actuator, not the whole valve

 

[uyevuye]

Our heating comes on when water heating is on. Normally only water heating should come on when hot water is turned on and heating should come on when heating is turned on.

I thought it could be wiring issue. So I have swapped around the motors to see the reaction. The one on the right was still malfunctioning. I turned the heating on when motors was not placed on the valve. Both motors worked correctly. That is the time I noticed that the right valve was the faulty one. As you said it is tight. Hope I can swap it. Otherwise engineer will come anyway. Possibly it will cost me around 200.00.

 

[uyevuye]

I have another question. While it is black Friday maybe I can invest on a new controller.
I want to have different timer and controls for the loft heating, rest of house heating and water heating as I have 3 actuators. Is it possible? Which controller can you recommend?