I am aware of the so called 'comfort' mode but I cannot afford the luxury of a 'nice constant temperature'. That's ok if I'm sitting around all day doing little but if I am busy dashing around doing jobs etc or if I to go out for half a day etc I want to turn the heating down or off I expect boiler to turn off until I feel I want it warmer.
With respect, that is not the issue you described in post #1. Your complaint was that the boiler was supplying the small amount of heat required to maintain the setpoint, which is what a correctly working modern system should do and it will be more efficient than using an on-off thermostat.
In post #9 you've changed your complaint and now seem to be saying that, for example, if the room temperature is 20°C and you reduce the thermostat setpoint to 17°C the boiler continues to supply heat to radiators even though you actually want the room to cool. If this is the case, then there is an issue that needs to be sorted out. Things I would look at, in order are:
(a) The communication between the boiler and thermostat. Some systems (I'm not sure about yours) will have a 'safe mode' that runs the boiler at low power when there is a communication fault to guard against frost damage.
(b) The thermostat configuration of the themostat. Although it looks simple, the thermostat contains a 7-day event programmer that can change the setpoint up to 6 times a day for heating and 3 times for hot water. If you just turn the thermostat down manually, the setting will only stick until the next programmed 'event' overrides it. (The way round this is to activate 'party mode' for the length of time you want your manual setting to stick.)
(c) Reverse circulation causing activity in the hot water section of the system to warm radiators as a sided effect. This is usually a plumbing / installation error.
(d) Depending on how your system is plumbed, a stuck-open zone valve may be constantly demanding heat from the boiler. The thermostat can't shut the valve but can tell the boiler to supply minimum heat.
(e) An incorrectly set parameter in the thermostat, e.g. a minimum room temperature that is too high.
The above suggestions are based on my memory of how the Greenstar 4000 and Comfort+llRF usually work together so may or may not be applicable to your system.
So, can a on/off thermostat be wired into the 4000? Thanks for your attention.
Yes it can.
But my suggestion is you get the installer of the system back to address your concerns. Installers are supposed to make sure that the system is working correctly and that the customer understands the controls and how it should behave as the final part of the commissioning exercise. It is not uncommon for customers who have boilers installed in the summer to discover problems only when the weather gets colder.
