CH Setup Query

[Stuart]

My Ch set up is a Pottertton Kingfisher CF 60 floor standing boiler,a Single Feed Indirect Primatic cylinder,pumped CH and Gravity Domestic( controlled by a thermostatic valve near to the cylinder) .I have rads in all the 6 rooms (2 in the Living Room) .All have TRV's and that is what I want to know .Should one of them NOT have a TRV...I have seen setups in friends homes where one rad ( in the bathroom) doesnt have a trv but maybe thats because of the type of boiler they have ...any help much appreciated . Stuart

[Ed Sirett]

With a gravity HW system there is no need for a bypass. However when you replace the boiler the new one may or may not require some permanent path for water to circulate.

[Set Square]

The idea of not having a TRV on one rad is that you have a room stat in that location, which provides a boiler interlock by switching the whole lot off when satisfied. This is only any use if the boiler interlock *also* applies to the DHW system. To achieve this with a gravity system, you need a cylinder stat and a motorised valve rather than a thermostatic valve.

All new systems have to have a boiler interlock to stop the boiler from cycling and wasting energy when all external demands are satisfied.

Unless you want to totally revamp your system - and go fully pumped - you can get somewhere close to half-way decent by converting it to a C-Plan system [See

]

Having said that, you really need to get rid of the primatic cylinder and replace it with a standard indirect cylinder and separate DHW and heating system header tanks. Then at least you'll be able to put corrosion inhibitor into the central heating.

[Mark]

.... and you also would benefit from a more effecient hot water system.

Mark

[Stuart]

Not so easy where I live in a tenement block of flats .The tanks would need to be in the communal loft two floors above me so I'll make do with what I've got . I dont pay any more for either gas or leccy regardless of how much I use .

Stuart