Installing Sunvic MK1453 3 port valve - A & B ports inve

[Ant1]

I recently had to replace a Sunvic MK1453 3 port valve, at first I thought I reinstalled the 3 port valve and the actuator exactly the same way as they were originally installed. Since the valve did not come with any instructions, I used the writing on the plate of the front of the valve for the valve orientation; the writing on the original plate was the correct way, i.e. from left to right, therefore I installed the replacement valve in the same manner. [I know... thinking now it was really not clever to use the writing on the plate for the valve orientation]

However I noticed I connected the A port to the cylinder (i.e. to the left of the photo) and the B port is connected to the pipe going to the CH. The actuator is actually correctly positioned; i.e. the domestic hot water arrow is pointing towards the cylinder while the Central Heating arrow is pointing towards the other pipe to the right.

MK1453 and DM5601 Top View

• Ant1
• 16 Dec 2012
• 2

I read that port A of a 3 port valve should go to the radiators and port B to Hot Water. Is this correct? If yes, what are the implications of inverting part A and B?

In my case, since the actuator is correctly positioned, can port A and B be freely interchanged?

It seems that the aperture on port B is slightly bigger than on port A, therefore I think inverting port A and B might be an issue.

I am trying to find out if reinstalling the 3 port valve is really required, trying to avoid draining the system again...

Note that my central heating is working fine (so far).

Thanks to anyone who could clarify the above.

Ant

 

[matt1e]

don't worry your particular valve is the correct way around

what are the implications of inverting part A and B?

if you have wired it correctly and it is the wrong way around then you will get heating when you select hotwater and vice versa
the stats will also be working the wrong zone, you would soon notice!

Plus the larger port goes to the heating, you're fine


Matt

 

[Ant1]

Thanks again Matt! I am relieved I do not have to reinstall this valve, it is located in a closet and really not easy to access.