Fitting an unvented cylinder to a combi.

[Meady]

Basically we went to look at a job this evening and the customer wants a unvented cylinder fitting to their combi boiler they already have fitted. As it stands at the moment they have a WB 38cdi classic with a inbuilt programmer that is attached to the boiler and a wireless WB room stat.

To get this to work am I right in thinking the programmer and room stat they have in there at the mo would need to be removed and a new say Honeywell one fitted on the wall???

Cheers

 

[lame plumber]

programmer will only be single channel so no use, whip it out and install an s plan via a wiring centre with any 2 channel programmer you wish with combined or separate rm stat. leave kitchen tap on combi rest on cyl, easy peasy

 

[Ermintrude]

As above

 

[Ermintrude]

Hope your 3G

 

[kris]

Hope your 3G

And wireless

 

[Meady]

I'm actuAlly 4g so one step better I'm presuming the pump will just kick in as normal whenever the boiler is told to fire up as that won't be wired up to the wiring centre like normal

 

[SafeGasInstall]

4G lol
3G is the unhw ticket

 

[AWheating]

I'm actuAlly 4g so one step better I'm presuming the pump will just kick in as normal whenever the boiler is told to fire up as that won't be wired up to the wiring centre like normal

the combi will be in essence a system boiler on an s plan, wiring as normally done with this type of install.

 

[buckley plumb]

as lame says - put kitchen tap on combi

 

[Ermintrude]

Pump will fire when u close the volt free contact for ch. It's not quite an Splan wiring

 

[townfanjon]

4G lol
3G is the unhw ticket

LOL LOL, classic !!!!!

 

[oz-plumber]

I have done this quite a few times, putting a DHW cylinder on a combi boiler.
I'm assuming that the cylinder will be a cylinder without a heat exchanger / coil installed.

The way i have done it is to disconnect the electric element from the electric supply and use the cylinder stat to control a pump.
When the cylinder calls for heat, it switches the pump on and activates the boiler for domestic hot water.
Have done this with 50, 80, & 125 ltr cylinders and the customers seem happy with greater hot water supply and greater hot water pressure, being that the cylinder is connected to the mains and the DHW is not going through the boiler.

I cannot foresee any problems

Oz Plumber