HW must be on with CH

[Santorium]

System is gravity fed with a pump for the CH.

Manual for electronic control states that the system can be plumbed in one of two ways:

1) CH and HW independent
2) HW must be on with CH

Mine is setup as option 2 and I'm wondering:

1) Why it would have been installed this way?
2) Would there be any significant advantage in cost savings by having it re-set to CH and HW independeny?

Does it really make much difference either way?

 

[cozzmic]

If you set your programmer to HW & CH separately you will find that even on CH your HW will still heat as there is no control to stop the HW gravity circulation. The way the programmer is set is the correct way and if you want more control you could fit either a gravity control valve or even a motorised valve to shut the circulation on the return, you must leave a clear path from the flow to the expansion/vent pipe hence valve on return and a cylinder stat to control the water temp or interlock with the boiler to shut it off when it's up to temp.
If you did it this way you could use the full programme facilities on the timer.

 

[Santorium]

Thanks for the detail.

If I were to do it, would it actually make much (if any) difference to gas bills?

 

[Mikeyboy]

Yes,save loads on your gas bill.