Is there such a device

[jc_150]

Hi all in the forum,
I seem to be perpetually tweeking my sytem to get it how I would like it, and am in my opinion close. I have a 6 rad 2 bed house with a Worcester Bosh open vented boiler system and hot water storage tank. I have fitted 5 Hive thermostatic rad. valves and have finally got them to do what I want. The 6th rad. in the hall has a TRV with the head removed as the bypass. (I did this because I needed a bypass as the boiler has pump over run and wanted to move the bypass from the bathroom rad to the hall rad. so that the bypass rad was doing some good rather than waste heat in an unused room after everyone was downstairs. (Have downstairs wash and loo facilites) As expected the hall rad is at full bore everytime I select a particular room valve to start heating as well. So enough ramblings. Is there a device and what is it called if there is one that I can screw onto the hall TRV and wind it in to say half way to still act as a bypass but not be full on everytime another TRV calls for heat. I have made searches on the net and getting results but not for the device I am looking for.
Thanks in advance of any replies.
JohnC

 

[gmartine]

It's called a lockshield valve and you should have one on the other end of your hall rad.

 

[Ric2013]

Assuming you already have the lockshield valve set correctly...

I have experimented with such an idea in my own house, though not with a TRV head. I installed a differential pressure ABV and connected it through a bypass radiator.

The problem was that water quality was poor and when the ABV opened, it got jammed partially open by shards of magnetite and the bypass radiator remained lukewarm until I dismantled and cleaned the ABV. After going through this process twice, I called time on the experiment. Since then I have powerflushed the system which should have improved the water quality, but I have also upgraded to a proportional pressure pump. Since a proportional pressure pump will not lift an ABV when flow is reduced, the two devices could not be used together successfully anyway, but perhaps you have an old, fixed-speed pump?

 

[gmartine]

I think we are way past worrying about a balanced system if you have Hive thermostatic rad valves on every other radiator. Wind down your hall rad lockshield until closed and back off half a turn and see how it performs, then repeat if necessary.
Your regular boiler wont modulate that well so I wouldn't heat up rooms on an individual/usage only basis, better to have it running at a lower temp for longer say set your flow temp to 55 degrees and see.

 

[jc_150]

Hi all,
Thnks for the speedy replies. never thought to adjust the other end of the rad. I have a grundflos alpha 2 pump, and the best differential pressure I get with clip on guages on the flow and return is when I set it to proportional 2. I get about 10 degrees C difference when the flow is at around 60 degs, but the return does increase when the rads are almost at temperature set. (about 3/4 of the way round the boiler temp dial as it does not have temps. on the dial) Will report back after having a tweek at the lockshield.
Thanks again JohnC

 

[jc_150]

Hi all,
Just to say thanks for the advice. I have re adjusted the lock shield on the hall rad which cured the issue I was having. This in turn seemed to make differences to the other rads, so been tweeking all the lock shields, and have the system working well now, even some gurgles I was having before seem to have stopped. so all well at the moment.
Thanks again
John