Honeywell 3 port valve fully open but no hot water

[yiano1234]

Hi, I have a honeywell 3 port vavle that is causing me so many problems! It has already been changed once and still problems persist.

Both the heating and hot water are on, on the programmer and both stats are calling for heat. The pipe going into the bottom of the 3 port is red hot, as is the one going to the rads. (rad all getting nice and hot). But the pipe going to the hot water cylinder is only luke warm and the pipe coming out the bottom of the cylinder is cold. If I turn the heating off, then the water flows around the coil to heat hot water.

So my problem is when both are on, the heating is taking priority. Which often means I have no hot water, as It only heats up if the heating gets up to temp.

Another problem - maybe related, is that when the house is up to temp the heating goes off. But then if the house cools and the heating should come back on, it doesnt. You have to go upstairs and manually push the 3 port open. It then remains on heating up house again.

Anyone any ideas?

 

[leakydave]

Have you removed any trapped air on the hot water side of the valve?

 

[yiano1234]

I think all the air is out, as when it is on hot water only it circulates fine.

 

[Whitespirit66]

Did you change the whole valve, or just the actuator head?

 

[oilhead]

There would appear to be a wiring or component fault. Is the new valve doing what the old valve did?
Have you checked the current in the junction box to the relevant wires on the valve?
My initial thoughts are a fault with the cylinder stat, but without doing the wiring checks, cannot be certain.

 

[Butchybutch]

Oilhead is right!

There will be a wiring fault there, sounds like a few people have had there fingers in it!

Download a wiring diagram for a "Y" plan, and check it.