conventional boiler v combi running costs

[matz]

The advice above is based on UNVENTED cylinders which are directly fed from the mains water just as a combi is.

The minimum mains dynamic flow rate is about 22 litres per minute @ 1.0 bar.

The cost of the cylinder is little more for a larger cylinder so don't bother to fit a small one. The rule of thumb is 50 litres PLUS 50 litres PER person. So 300 litres for up to five people.

Cylinders about £800 and installation about £500. But the mains water supply capability needs measuring before considering an unvented ( or a combi for that matter.

An unvented will supply several outlets at a time unlike a combi which has a very limited flow rate.

Tony Glazier

do these cylinders cost alot less to run than a vented one? Theres a big cost difference in buying.....

 

[matz]

do you have to be Gas Safe Reg to put a mains fed cylinder in?

 

[St0rmer66]

Cost about the same, the advantage is that the hot water is at mains pressure rather than relying on gravity/header tank in the loft to feed it.

Not "gas safe" BUT there is a qualification for it (G3) which is needed to install/work on them.

 

[Dan Robinson]

do you have to be Gas Safe Reg to put a mains fed cylinder in?

No but you do need a valid G3 certificate and it will need registering with the local authority.

 

[Dan Robinson]

do you have to be Gas Safe Reg to put a mains fed cylinder in?

No but you do need a valid G3 certificate and it will need registering with the local authority.

 

[matz]

interesting. I never knew that.....