Wiring help

[Bhoydavid]

Evening, looking for some wiring advice. Got a vokera mynute 15vhe heat only boiler. When I put the programmer (Horstmann 425 diadem) on for hw only the pump runs bringing the ch on. So basically I can't have hot water only. Anyone have any tips? There is no zone valves.

 

[ShaunCorbs]

hot water is on gravity (no pump) pipe should be 28mm

heating is with pump on (hot water also)

needs updating tbh

 

[Bhoydavid]

hot water is on gravity (no pump) pipe should be 28mm

heating is with pump on (hot water also)

needs updating tbh

Ideally would've fitted zone valves or went to a combi but we are the pearl of the custard.


What hat I don't get though is how the ch comes on when the demand is only for hw. It's been wired the exact same as the old boiler.

 

[ShaunCorbs]

Ideally would've fitted zone valves or went to a combi but we are the pearl of the custard.


What hat I don't get though is how the ch comes on when the demand is only for hw. It's been wired the exact same as the old boiler.

boiler would still come on but pump wouldnt so if you have wired the pump to the boiler both would

 

[Bhoydavid]

boiler would still come on but pump wouldnt so if you have wired the pump to the boiler both would

How will I fix this mess? I've spent about 6 hours trying various combinations and just praying:smilielol5:

Close to tears

 

[ShaunCorbs]

How will I fix this mess? I've spent about 6 hours trying various combinations and just praying:smilielol5:

Close to tears

either update which i would go for (but you could just put a 2 port on the heating but i would go full hog)

hot water = just boiler coming on but have a feeling over heat thermo stat will kick in / no flow through boiler

heating = pump and boiler come on

 

[firemant]

Is this a new boiler? If so, how have oyu fitted on gravity?

 

[stani]

Have you just fitted a new timer,
is it set to gravity hot/pumped ch.
Sounds like the h/w and ch are wired the wrong way

 

[gassafe]

Sounds like installation fault...

No zone valves on a new boiler?? Rads will always get hot if there's no zone valves but the pump comes on!? The new boiler would not exactly work on gravity...

 

[Nostrum]

You shouldn't have installed it like that to be honest.

Under part L you need to provide independent time and temperature control to heating and hot water. Impossible with out zone valves.

 

[Bhoydavid]

Cheers. I wasn't aware of the issue of no zone valves. Arranged to go back and fit zone valves and get it zoned off.