A bit like Harry, I have a condensing boiler (all be it a heat only boiler with no internal pump control) with existing controls, all be it “dinosaur age” controls. Simply consists of a wireless room stat, timer and TRV’s. I have no intention or desire to spend hundreds of pounds upgrading the controls for something which will take years to break even on with savings. I don’t even think my BG 330 has the capability for things like weather compensation? Thats what our last Gas Safe man said at the last service anyway. Who am I to disagree? If that’s false please let me know.
Anything done in the way of improvements, has to have a financially worthwhile or comfort reason, or it is not worth doing. I was in the situation of a forty year old system, fitted with a later replacement heat only condensing boiler, which was unreliable and operating on very basic controls. The boiler was unreliable, so I decided time for a new, much more modern one which I installed still on my original very basic controls, with it's constant wide swings in temperature, as the boiler cut in and out. Whilst the system was drained, I added wax TRV's too.
Having got that far and heat back on, I looked at options for upgrading my old control system and what my new boiler directly supported. I bought and installed a complete new system, which included an outdoor sensor weather compensation, plus manual compensation for the environment it was in. I then spent weeks tweaking it and trying it's various settings, until I got out of it just what I wanted - a system which was unnoticeable in operation. The lack of over-shoot, was most noticeable when the stat is adjusted to increase the temperature - now it comes on, then just gently ramps down as it nears the demanded temperature, rather than over-shooting the setting.
Once at temperature, it just holds it there with a steady trickle of heat input, rather than either heat or no heat. So a big bonus in comfort and some economy.
I was always under the impression that only heating some spaces led to more heat loss than heating it all up together?
In my opinion, that depends upon how big a home you have, how you use it and how well insulated it is. I have a medium to large sized 3 bed 1955 semi, which I upgraded over the years with CWI, DG fixed all of the many air leaks and added properly controlled ventilation. It was horrendous when I first moved in, absolutely freezing in winter. We generally have all internal doors open, unless it is very cold. Unless you have a big rambling home, with sections unused most of the time, there is not much point to zoning. If zoned to have the upstairs off in the day, heat will rise anyway.
On and off, plus actual temperatures are simple - It is always on. Night temperature is set at 16C, it never gets that cold in here, day temperature is 18C, which I might nudge up to 20C if we feel chilly.
I just want to work with the existing controls and boiler to make them work a little better - even gaining a couple of percent worth of efficiency at the boiler if I can keep the return temp at 55 degrees or lower for longer.
if my rooms are over shooting, what can I do about that? Balance down a bit?
If you don't have one already, you cannot beat having a boiler which is able to ramp it's output down to match the needs of the house. The more it can ramp down the better. Even better with a control system which can predict 'tell' the boiler how much output is needed in a heating cycle.
As a quick and simple fix and an idea for the experts to consider - Add a pipe thermal switch /stat. set at what you consider to be a maximum return temperature and wired to inhibit just the boiler? You can buy clamp on to the pipe type stats. and it would go right next to your boiler, but might make you boiler cycle even more?