Thermostatic Radiator Values

ifti

hi,

we are looking to install a new raidiator in our loft as we have a average sized room there, we have pruchased quite a big radiator but think its best to install a TRV too.

looking at screwfix we have a choice of either a Drayton RT212, Pegler Terrier II or a Honeywell Radplan 120, all wax sensors, not sure how much slower in reaction time they are compared to a liquid sensor and only the Pegler Terrier II has 5 yr warranty the rest dont have warranties specified,

can anyone recommend me one of these ?

thanks in advance

ifti

EliteHeat

Get the Drayton TRV4 from SF, easily the best there is.

ifti

thanks for the info, any idea how much slower in reaction they are compared to wax sensors ?

ifti

just a thought but will a TRV put less pressure on the boiler pump when the heating is on for a few hours ?

rather than continous pumping it will slow down when it the TRV kicks in, seems logic unless i havent understod how the boiler pump works.

barrymung

ifti wrote: »

just a thought but will a TRV put less pressure on the boiler pump when the heating is on for a few hours ?

rather than continous pumping it will slow down when it the TRV kicks in, seems logic unless i havent understod how the boiler pump works.

You must provide a "bypass" on the heating circuit. This is usually implemented by NOT fitting a TRV to one of the radiators in the house, usually in the same room as the room stat.

That way, when the house gets hot and the TRV's close the pump can still circulate water round the non-TRV'd radiator.

If TRV's were fitted to all the radiators, or no alternative bypass provided, then the pump could get damaged.

(Note: Some boilers have an internal bypass device)

economiser

barrymung wrote: »

You must provide a "bypass" on the heating circuit. This is usually implemented by NOT fitting a TRV to one of the radiators in the house, usually in the same room as the room stat.

That way, when the house gets hot and the TRV's close the pump can still circulate water round the non-TRV'd radiator.

If TRV's were fitted to all the radiators, or no alternative bypass provided, then the pump could get damaged.

(Note: Some boilers have an internal bypass device)

This is of course for 2-pipe systems. With single pipe systems there is no need to do this. I do admit however that 2 pipe systems are far and away the most common arrangement in the UK, not sure why as single pipe systems are cheaper and quite adequate for domestic purposes.