Unvented heating and hot water

[Viper Gas]

Hello all

I'm installing an unvented vaillant unistor cylinder. The parts in the box includes a single two port valve.

Thing is there is no 3rd party wiring diagram in the installation manual showing how to wire this two port valve into a y plan system.

Has anyone got that diagram? I have contacted Vaillant but they are slow in response.

I'm BPec unvented qualified.

Cheers

 

[ShaunCorbs]

On a y plan system wire the two port to the safety thermostats

Eg when upto temp eg 60 the port valve closes

TBH convert the system to an s plan

 

[chris watkins]

Just incase you still needed the wiring, the Vaillant stats connections replace the Megaflo ones as follows
1 = 1 on high limit (upper part).
2 = 2 on control stat (lower part)
3 = 4 on control stat (lower part) the terminal marked with the 1 in a circle.

 

[Sharp Point]

On a y plan system wire the two port to the safety thermostats

Eg when upto temp eg 60 the port valve closes

TBH convert the system to an s plan

Yep, second that

 

[townfanjon]

Thirded , if theres such a word .

 

[Harvest Fields]

I agree with @ShaunCorbs also. Less messing around.

 

[chris watkins]

How would you wire it in then?
Live through the control & high limit to Brown of 2 port from where ?
& are you going to wire the end switch ?

I would never use a 3 port with an unvented so just interested as there are a few around,

 

[ShaunCorbs]

two ways

if you cant get back to the multi way/system wiring centre

take your power from the immersion and make safe the rest of the wires

or the better way

take your power from the hot water on link it through the stat and then to the valve

 

[chris watkins]

two ways

if you cant get back to the multi way/system wiring centre

take your power from the immersion and make safe the rest of the wires

or the better way

take your power from the hot water on link it through the stat and then to the valve

I think I will stick to the MI's, immersion sound like having a double feed into the controls wiring to me & not so sure of any benefits the other way as you still have to run it through the stats.

 

[ShaunCorbs]

I think I will stick to the MI's, immersion sound like having a double feed into the controls wiring to me & not so sure of any benefits the other way as you still have to run it through the stats.

They wouldn't be connected as you couldn't get wires from the heating eg not accessible

So the port valve would act on its own via it's own fused spur from the immersion etc

 

[Viper Gas]

Hello
Thanks very much to all those who gave input. Here's what I managed to get from Vaillant which looks good to me.

Only question is, how does the 3 port get a signal to move to hw mode?

Why this diagram is not in the manual is beyond me.

 

[ShaunCorbs]

Via the orange wire off the two port