I've replaced all our 1970's TRVs with new Draytons and am having real problems getting each valve's temperature drop to be what the online guides suggest (11-12deg).
The boiler's a Worcester Greenstar 29CDI fitted in 2016.
I liked the idea of using the TRV4 to do the job of the orginal lockshields so I set them all (lockshields)l to max flow (fully ccw) and all the TRV4's as supplied (max flow setting "6").
As I understand it, I should determine and list which radiators heat fastest (with all the TRV heads removed) and then allow the system to cool.
Then, with a pair of digital thermometers attached to the radiator pipes starting with the fastest one, turn it CW initially to "1" and adjust it to achieve the required 11/12 degree difference. Then move on to the next fastest and repeat.
My first questions are,
1. Do I measure the pipe temperatures as it's been heating up for ~15 minutes?
2. When it's at its hotest but the boiler is still heating ~20 minutes?
3. When the boiler is no longer heating the water just circulating it ~25-30 minutes?
I've tried all three (literally dozens of measurments and several pages) but in each case, on moving on to the second, third and forth rad's, the valves all need to stay on setting 1 - in fact it seems as if even that flow rate is too high!
Leaving the downstairs rads' at any of those settings and moving upstairs gives similar effects, in fact only one upstairs rad needs setting to 2.
Also, two radiators are literally back-to-back either side of a partition wall and with thermometers on each at the same time (got four thermometers), as they heat to near the max temperature, the readings on the return pipes jump several degrees then very quickly return to what thet were - as if they were somehow oscillating. I can't see them both together so can't tell if they both rise at the same time or if one rises as the other falls.
In case I'm missunderstanding the TRV4 operatton, is the following correct.
TRV setting 1 = Lowest flow rate, Highest return temperature, Lowest temperature difference
TRV setting 6 = Highest flow rate, Lowest return temperature, Highest temperature difference
Confusingly the TRV4 flowrate adjustment is the opposite way to Lockshields - CW rotation on a Lockshied reduces the flowrate.
Any sugestions please
The boiler's a Worcester Greenstar 29CDI fitted in 2016.
I liked the idea of using the TRV4 to do the job of the orginal lockshields so I set them all (lockshields)l to max flow (fully ccw) and all the TRV4's as supplied (max flow setting "6").
As I understand it, I should determine and list which radiators heat fastest (with all the TRV heads removed) and then allow the system to cool.
Then, with a pair of digital thermometers attached to the radiator pipes starting with the fastest one, turn it CW initially to "1" and adjust it to achieve the required 11/12 degree difference. Then move on to the next fastest and repeat.
My first questions are,
1. Do I measure the pipe temperatures as it's been heating up for ~15 minutes?
2. When it's at its hotest but the boiler is still heating ~20 minutes?
3. When the boiler is no longer heating the water just circulating it ~25-30 minutes?
I've tried all three (literally dozens of measurments and several pages) but in each case, on moving on to the second, third and forth rad's, the valves all need to stay on setting 1 - in fact it seems as if even that flow rate is too high!
Leaving the downstairs rads' at any of those settings and moving upstairs gives similar effects, in fact only one upstairs rad needs setting to 2.
Also, two radiators are literally back-to-back either side of a partition wall and with thermometers on each at the same time (got four thermometers), as they heat to near the max temperature, the readings on the return pipes jump several degrees then very quickly return to what thet were - as if they were somehow oscillating. I can't see them both together so can't tell if they both rise at the same time or if one rises as the other falls.
In case I'm missunderstanding the TRV4 operatton, is the following correct.
TRV setting 1 = Lowest flow rate, Highest return temperature, Lowest temperature difference
TRV setting 6 = Highest flow rate, Lowest return temperature, Highest temperature difference
Confusingly the TRV4 flowrate adjustment is the opposite way to Lockshields - CW rotation on a Lockshied reduces the flowrate.
Any sugestions please
