Anti-cycle software & Greenstar 24-28 i Junior Combi

[ericmark]

First job was set lock shield valves, better but not right, next was turn down all the TRV then back up bit at a time until room some where near, on an over cast day not bad, but clear sky was a problem the bay windows down stairs catch the sun, up-stairs near enough, but down stairs was a nightmare, so started a string of attempts to get the two rooms some where near, the pair of eTRV's helped.

However your comments about putting a thermostat outside even if in error did go through my mind, after some experiments I realised TRV's gradually open and close and in turn by what ever method control the boiler. But it was the turning off the boiler when no longer needed which is the problem, in hind sight I should have gone for EvoHome, however now I have the hub and two Energenie eTRV's not inclined to bin them and start again.

So I have tried a compromise with standard TRV and wall thermostat both in hall, and it does to an extent work. However if I can understand how the boiler works, maybe then I can better work out how to control boiler? What is left to sort out is how to drop temperature at night and raise it again during the day.

 

[DP]

For your system what I would do is as follows
Open all TRVs
Run boiler at a say 70 degrees and let all rads heat up
Now check the temperature of the two pipes at every radiator- aim for say 20 degree difference. Adjust lockshield to achieve this. This task is time consuming
Once this is done, set TRVs to temperature corresponding to the rooms. Example lounge 20, hall 18, bedrooms 16 and bathroom 25
Instal a programmable room thermostat in colder room (room that is hard to heat)
Set above thermostat to three levels of heat..... comfort level, background heat (when you are active) and about 10 when you are asleep or not at home.

Let the system run to this and tweek for fine tuning only.
Where the thermostat is located, remove TRV or set it to max

 

[ericmark]

I have set lock shield valves and as you say it took some time, I have set the TRV in up-stairs rooms, and down-stairs set the eTRV in two main rooms with varying temperatures according to time of day. The next bit not so easy.

Install a programmable room thermostat in colder room (room that is hard to heat)

I bought a programmable room thermostat a Horstmann HRFS1 however I have found it will only work in the kitchen facing the base unit stuck to the oven, which is not really a good place for a thermostat, move it further away and it fails, it has both stuck off and on when moved further away, tried moving the code pegs and using a different code but it still fails.

The Honeywell ST9000 programmer and Y6630D thermostat work fine, the sensing unit is in the hall and in the picture you can see Honeywell above consumer unit and Horstmann below it. All the Horstmann does is give a boost to 22°C first thing in the morning to keep boiler running longer so other two down stairs rooms have chance to heat up. After that boost the Horstmann switches off.

The hall has a very large radiator as shown to both dry coats and to reheat hall once the front door is opened, if the lock shield valve was throttled back then other rooms warmed up, but on opening front door hall would get cold and would take hours to warm up again, open the lock shield valve and hall heated up, but then other rooms had problems. So I fitted the TRV to hall radiator, took some setting up, but it now works, the TRV starts to close at 17.5°C but is not fully closed until 19.5°C the wall thermostat set to 19°C so if front door opened then hall reheats quickly to 17.5°C then starts to slow down allowing rest of house to get warm before it hits the 19°C when the wall thermostat will turn off the boiler. It works I got it set up in Spring. However it means I can't really alter the temperature set with the thermostat or TRV as it took so long to get the balance to start with. I can switch heating on/off but can't turn down the temperature of hall at night.

Hence trying to get head around how boiler worked so I could do something to reduce night temperature. Main problem is the small bedroom upstairs, above kitchen it has all the central heating pipes under the floor and the radiator is hardly required as it has in essence under floor heating due to pipes. If my mother did not sleep down-stairs it would be easy, simply set the programmer to turn off central heating at night, as enough heat raises to keep up stairs rooms reasonable through the night, but her room without some heating running gets too cold.

This post has helped in two ways, one ideas from others, and two getting me to think more. As I have sat down writing I realised I have an option requiring nothing but altering setting. What I need to try, and clearly must wait for Winter, is to set that kitchen thermostat to control night temperature, and hall thermostat day temperature. Don't know why I didn't think of that before. There is only one day it may not work, Christmas eve, that is the only time the oven runs over night, by 7 pm no more cooking so by 10 pm could use kitchen rather than hall.