Postby OLBC Group » Mon Oct 28, 2024 8:10 am
There are two main systems we install.
Honeywell for mixed underfloor and radiators.
Heat Miser for just underfloor.
Both have excellent apps. It takes a while for the system to learn.
If radiators are radically mis sized this can cause issues with over under shoot.
It is also worth considering that if the TVR valve pins are sticking on the thermostatically controlled side this can cause over/under shoot. It is relatively simple to check this out - just put a coin on top of the pin and press it a few times - the pin should move in/out quite easily. It is worth trying a tiny drop of lubricant and cycling the valve a few times manually to see if it frees up. Sometimes the only solution is replacing the TVR. Cheap generic TVR’s are generally worse in this regard.
The Honeywell is DIY setup able if you already have a Honeywell wireless stat controlling the boiler. Some of the setup button press sequences are insane and the location of some of the buttons is a head scratcher. I have Honeywell at home and it is very robust and makes clear savings of gas volumes used.
Heatmiser requires more knowledge to install and configure. We have historically fitted loads of the earlier systems. The newer systems branded Neo are much much better and we fit those to all houses with UFH.
The thing that really makes the difference is having a temperature compensation device. This sets the CH flow temperature higher as the outside temperatures falls. Unfortunately they are rarely fitted in the UK but compulsory in Germany - sadly British plumbers don’t understand boiler control systems. That is a result of plumbers being untrained and Gas Safe being a short course.
If you can have a temperature compensator fitted you really should - not all boilers can have one fitted.
The lower the return temperature the more efficient the boiler is. Obviously when it gets really cold outside, for those two weeks every other year, things need to go up a gear and that is when the compensator helps. Equally you can just set the CH flow temp as low as you can with the house being warm enough for you and then manually turn it up - not as elegant!