Help! Confused and Shortchanged

[Mark2010]

My house recently underwent a renovation and the plumbing was totally redone however I still have outstanding issues that need explaining.

The rads are old cast iron types that are fitted with TRV on all rads. There was no provision for rooms stats up or down stairs, if I set the TRV to a set level when this is reached will it shut down the boiler and the pump.
Should I fit a room stat if so what will this do for me?

There is underfloor heating down stairs and with it came a four channel clock but I'm told I'll have to put 3 seperate clocks in the hot press to control rads upstairs, rads down stairstairs and hot water

Will this be efficient, there are 2 vokera modulating boilers that I'm told will run together not one for u/floor etc.

Thanks

 

[DP]

Mark the boiler and the pump is not controlled by the TRVs. All that will happen is TRVs will close and no water will flow through the radiator when that room has reached the set temperature. Pump will continue to run. Boiler may shut down to cool of to fire again.

Fitting a programmable roomstat will be effective and save you pennies as well.

The fact that you have four zones, (Underfloor, down stairs which I assume is non underfloor zone, upstairs and HW) are these controlled by motorised valves? Each zone would then require some sort of timer and thermostat. With motorised valve you get independent timed control of zones. You would also be able to select what zones will fore what boiler.

Perhaps you installer's control skills are a little hazy.

 

[Mark2010]

Hi DP,

People are mentioning that one rad should have a non TRV and bypass circuits. There are motorised valves in the hot press, are there wireless room stats you can buy as it would be impossible to wire back to the main controller?

 

[ianniann]

Typically you need at least one radiator that will always be open so that the boiler and pump have somewhere to send hot water, although a new installation should also include a bypass which would at least prevent damage if all the rads were closed. The standard installation would have a room thermostat in the room with the permanently open radiator so that the whole system will shut off when it gets warm enough. All other rooms would have TRVs to shut down each radiator as its room gets warm enough.

You can certainly get wireless controllers, from the very simply to the very complex. It sounds like you may want something slightly more complex than a simple time clock and thermostat for all those zones, but maybe not.

 

[DP]

Mark if you can run 4 core cable to points where thermostats are to be sited, you will then be able to use the 4 channel timer (if this allows independent timing)

If not possible to run cables, use radio control. Danfoss radiuo control will give you three independent chanels one of which can be controls for use with HW cylinder.

Bypass is mandatory. When all zones shut down and pump still running, water then flows through the bypass and nothing else.