Well tonight I am able to confirm it's nothing to do with lock shield valve settings or the thermostat or the TRV's they are all working A1. The problem is simple the eTRV's are not changing temperature as set. Two nights same results, at 8 pm and 10:30 pm the bedroom and the living room eTRV's are set to reduce temperature from 19°C to 16°C before the change target 19°C current 19°C and target 19°C current 18°C at 4:50 am I am recording target 16°C current 19°C and target 16°C current 18°C the temperature in the rooms door closed has not dropped even 1°C with outside temperature of 11.8°C air and in garage 11°C.
The baby alarm shows 21°C in bedroom and the camera shows 18°C in living room confirming the temperature in the two rooms has not dropped. It is clearly a problem with the eTRV's not actually altering set temperature not any of the setting set by the user (me) in hind sight the much cheaper self contained Pegler Terrier i-temp i30 programmable radiator valve at £22.51 each would have done a better job than the Energenie MiHome Smart radiator valve at £72.99 a pair a saving of £27.97 for the pair.
Unfortunately for me, until the general house temperature was held stable with the TRV fitted in the hall I was blaming water flow available to the valves, rather than the valves.
As to the lock shield valve settings, for a central heating system running 24/7 with TRV's on every radiator there is I agree no need to set the lock shield valve, it can be left wide open, they only do any good as the property is warming up from cold, once warm they are not required. Without setting the lock shield valves on warm up you would get the easy flow rooms warm up first and as each TRV starts to close it will force water to remaining rooms all well and good if doors closed, if open you can have a situation where the boiler is getting returned hot water and so is reducing flame height, but the room can't warm up enough because of the open door to turn off the TRV. So if piped in parallel as in domestic then if there is any time clock so system will be starting from cold then you need to set the lock shield valves. With a series piped system as with most commercial premises then you would not want to close down the lock shield valve except for radiator removal.
With 42 radiators I would class it as commercial and likely piped in series rather than parallel, in my own house I have a Myson radiator which would work very well piped in series, with old boiler I have it works OK as return water temperature is not a problem. It needs a wide open lock shield valve as the thermostat is electric and starts and stops the fan. If the lock shield valve is closed every time the fan starts the radiator will quickly cool and the water temperature sensor will switch the fan off again to stop it blowing cold air. This is one of the reasons I have never had a condensate boiler fitted, the Myson would need to be altered to work with a condensate boiler, or ripping out and a massive standard radiator put in to replace it.
However in my mother's house there is no question the lock shield valves should not have been left wide open, although I can see a problem fitting a system in the summer and setting the valves spot on, it is very hard to calculate how much heat will go upstairs, specially with this house with coats hung over the radiator in the hall and a massive heavy curtain which can be drawn around the entrance to the stairs, although curtain no longer used. All the installer can do is close the valve and then open a set amount, he can't really set the valve until winter arrives. But since the system was altered so domestic hot and cold water to shower were direct from mains rather than from a header tank, the shower should have also been changed from a power shower to just thermostat controlled shower, not doing that was not only bad practice it was illegal, so there seems to be a failure on the part of the company to ensure their workers were trained to the required standard.
As an electrical engineer I did not physically do all the work myself, however I was responsible to ensure those under my charge did the work correctly. Nothing wrong with electricians and plumbers mates or apprentices, but the electrician or plumber does need to check what they are doing. The
Emma Shaw Case is typical of what happens when the management fails to monitor what is going on. I felt sorry for the foreman, what he asked of the worker was so simple, plug in the meter and write down the readings, I am sure he never considered, that if the meter did not show a reading, that the worker would have asked his mates in canteen what to write down, and fudge up some results, but that is what happened.
) The quantity of heat half a dozen bodies produce can be quite surprising.
