Mid position valve and underfloor heating

[Geordie Spark]

I wanted to check that the internal wiring wasn't shorting out etc and curiosity.

Curiosity killed the bat. ....... or something like that.

 

[Mork]

Also when the UFHeating switch wire is disconnected from the orange, the system as it originally was works perfectly, hey ho looks like im back on site tomorrow continuing to isolate the problem.

 

[Mork]

If any one does have any suggestions Id be glad to get your responses, but the football is on now so wont be replying.

 

[davesparks]

Also when the UFHeating switch wire is disconnected from the orange, the system as it originally was works perfectly, hey ho looks like im back on site tomorrow continuing to isolate the problem.

Eh? Which switch wire from which orange?

Draw out a diagram of the wiring and post it here if you want the best advice we can give.

From what you have described so far there must be 3 orange wires to fire the boiler, one from the three port, one from the ufh and one from the 2 port valve providing the positive shutoff for the unvented cylinder.

 

[davesparks]

If any one does have any suggestions Id be glad to get your responses, but the football is on now so wont be replying.

If you can be bothered to reply, don't expect anyone else to!

 

[D Skelton]

I'm surprised Scouse Tel isn't jumping all over this thread.

He knows all there is to know about UFH heating!

I'm surprised that the op didn't rip out the 3 port valve and replace with three 2 port valves?!

Or at least get the plumber to do the job right in the first place?!

 

[davesparks]

I'm surprised that the op didn't rip out the 3 port valve and replace with three 2 port valves?!

Or at least get the plumber to do the job right in the first place?!

It is an odd one, as they appear to have installed an unvented cylinder aswell as the ufh so the 2 port used for the positive shutoff means the plumber must have installed an automatic bypass into the system now.
The bypass isn't needed with just a 3 port as it spring returns to HW open, but you need a shutoff in the flow to the cylinder if unvented so that the flow stops if the overheat stat trips.

So all the advantages that I understand a 3 port to give have now been lost.


Bug then you can't trust a plumber to do the right or sensible thing can you?
The last Y plan system I wired the plumber had neglected to install the 2 port for the unvented or a bypass and I had to explain to him his mistake and point out the relevant parts of the MIs and draw a diagram for him!

 

[Geordie Spark]

I'm surprised that the op didn't rip out the 3 port valve and replace with three 2 port valves?!

Or at least get the plumber to do the job right in the first place?!

That would be my choice as well.

 

[Mork]

If you can be bothered to reply, don't expect anyone else to!

Absolutely right ,appologies , the orange wire is from the 3 port zone valve connected to it are the input from the underfloor heating and the output to the boiler, when im calli g for heat from the ufheating the valve on hot water opens and 3 port allows the rads to heat up , its seems to be the case that when 230v is applied to the orange from the ufheating the white from the 3 port valve also livens up !

 

[Anthony S]

To do it properly you need to Zone Valve UFH, CH, HW, its that simple.

 

[davesparks]

To do it properly you need to Zone Valve UFH, CH, HW, its that simple.

Although it's a bit odd the setup he has can be made to work if connected properly