TRVs. Cheap or expensive?

[HawkEye244]

This is really a question for plumbing section but what is the difference in performance between the cheap TRVs and the expensive ones? Some are quadruple the cost of others. The stock basics ones starts at about £5

 

[muggles]

The differences are in the type of sensor used and the quality of the mechanism within

 

[Dan Robinson]

Best cheap programmable stat that doesn't need a degree in hieroglyphics to run is the Center Brand wireless one, although I hear they've hiked the cost big time.

After that, the T4R is pretty damn clever for the money.

 

[ericmark]

This is really a question for plumbing section but what is the difference in performance between the cheap TRVs and the expensive ones? Some are quadruple the cost of others. The stock basics ones starts at about £5

I would also like an answer to this question. Assuming the head will be taken off and replaced with some electronic type, and we are selecting a valve which can be mounted either way around. Is there really any point in getting an expensive valve?

And as part two to the question for the heads we see.
* - Liquid sensor.
* - Wax sensor.
* - Electronic sensor.
I would assume since wax is more expensive that is better, and since electronic more expensive that's even better, I realise there is a temperature at which fully closed and a temperature when fully open, but what is the range between fully closed and fully open? I know when I swapped the existing heads for electronic heads the room temperature was far better controlled, however how much was due to being able to set to 20°C rather than number 4 I don't know. I know my Energenie has two sensors one for air and one for water and it uses water temperature to compensate the air temperature reading so radiator being hot will not affect the reported room temperature. But do they all do that, or is it special to Energenie?

£47.38 to £4.89 is a huge range. (Screwfix prices not counting 3/4" pipe one) how much because it has chrome and how much because it works better? so if we get the £4.89 valve and stick a £22.51 Pegler Terrier i-temp i30 head so total £27.40 would This Pegler valve be actually better with a liquid sensor? Even when it is not programmable and does not have a centigrade scale?

 

[Madrab]

" ...... thump ...... "

 

[HawkEye244]

Some futher info would be a good on this. A plumber friend of mine says it's just a brand thing. Further info needed...

 

[muggles]

Wax sensors are the cheapest and least accurate
Liquid sensors generally cost a bit more but react more quickly to changes in temperature, keeping the room temperature more constant
Electronic sensors such as Honeywell's HR92 are the most accurate, but at higher cost. They do have the advantage of being app-controllable though.

As far as the bodies go, some can be used for balancing a system, others can't. Danfoss ones (my usual choice) can be adjusted for flow direction, making them the only truly bi-directional valve. Some have larger orifices than others, different mechanisms etc etc

 

[Hot&Cold]

A plumber friend of mine says it's just a brand thing.

Yes,to a certain extent as many cheaper ones use the exact same unbranded valve body with the m30 1.5 sensor thread,
the same valve body can have different finishes,very blingy chrome,naff gold,nearly nickle plated or just plain contract chrome finish.
Different quality of sensors are available as mentioned by muggles, they will fit the above valve bodys some sensors are just rebranded/repackaged items for different companies/sheds.

just buy a known Well established brand.

Professional installers know the best trv's to buy to match the system they are being fitted to,diy buyers will most probably the cheapest and expect it to match a product 3 times more expensive.

there is a vast choice of trv's,professional installers know what works and often keep to the same brand.preventing call backs etc.

My choice is the RAS-C2 Target price £9.00 delivered.