Y plan 3 port valve problems

[ratmanuk]

Morning all after a bit of help please. we had problem with the mid port valve a few weeks ago as the heating would not come on only the hot water.

Engineer came out and replaced the top bit as it had burnt out. how ever the water in the tank is now scolding hot and the thermostat on the tank does nothing. i have turned it down to 40c but its still coming out at over 80c.

Not only that few of the radiators upstairs get hot but nothing down stairs any idea's on what's going on please?

 

[Exedon]

That looks a mess is white wire actually connected to anything?
You need a multimeter and be competent to use it
Have a look online for Honeywell Y plan writing diagram
Don't matter if its not a Honeywell valve colours are same.

 

[terryplumb]

Do radiators upstairs get hot when only domestic hot water is selected on programmer. ??
Or is that a separate issue altogether ?
What temperature is the boiler thermostat set to ?

 

[Johntheo5]

Here's the Y plan schematic, may be of help.

 

[oldbuffer]

1. May be my eyesight, but I can't see the brown wire coming from the valve connected to anything in "the wiring centre".
2. Normally only a 28 mm motorised has a sixth, white, wire. This is normally only used with a genuine gravity hot water system, and for a fully pumped system is not connected, as in the photograph.

 

[Exedon]

1. May be my eyesight, but I can't see the brown wire coming from the valve connected to anything in "the wiring centre".
2. Normally only a 28 mm motorised has a sixth, white, wire. This is normally only used with a genuine gravity hot water system, and for a fully pumped system is not connected, as in the photograph.

Correct re white wire on a zone valve on Y plan white goes back to room stat no brown wire.

 

[Johntheo5]

There doesn't seem to be anything connected to the white wire so the valve cannot move?

 

[Exedon]

There doesn't seem to be anything connected to the white wire so the valve cannot move?

That's certainly what it looks like!

 

[fixitflav]

Morning all after a bit of help please. we had problem with the mid port valve a few weeks ago as the heating would not come on only the hot water.

Engineer came out and replaced the top bit as it had burnt out. how ever the water in the tank is now scolding hot and the thermostat on the tank does nothing. i have turned it down to 40c but its still coming out at over 80c.

Not only that few of the radiators upstairs get hot but nothing down stairs any idea's on what's going on please?View attachment 320591

I've got attached Y-plan wiring diagram from somewhere. It's rather blurred, but studying it, I think the boiler and pump run any time HW Off on the timer (so HW off live) even when the cylinder stat is satisfied. That would give your symptoms. Maybe your man has wired it like that. If so, needs rewiring like johntheo5's #4. In the meantime, you could set the timer to constant HW, at least it then goes by the cylinder stat.

 

[Johntheo5]

It looks like the cylinder stat is bypassed or not working because the cylinder is reaching what looks like the boiler target temperature, the schematic above is incorrect, I've seen it before, the wire from terminal 6 should be going to C (common) on the cylinder stat like shown in my schematic.

 

[fixitflav]

It looks like the cylinder stat is bypassed or not working because the cylinder is reaching what looks like the boiler target temperature, the schematic above is incorrect, I've seen it before, the wire from terminal 6 should be going to C (common) on the cylinder stat like shown in my schematic.

Agreed