Jamieh1987

The problem I’m having is I’ve adjusted the boiler flow from 35-65, adjusted the manifold temp from minimum up to 55. Tried all sorts of combinations and they all seem to consume roughly the same amount of gas in £ give or take a few pence. It just seems like no matter what temps I set the boiler is firing at more or less 22kw for the each hour it’s on (but only with UFH), it’s a brand new Baxi 830. I’ve been running it at the higher temp for 2-3 hours to get the overshoot and that sees us through until the next day which I understand is not the best way to run it. Seems like if I lower the temp, run it for 2-3 hours, it costs me the same but is considerably cooler. I’m just looking for a more consistent temperature 24/7, more so for weekend. I’ve reduced the mixing valve to minimum and just set all thermostats to 19 degrees so I’ll see how that goes for the next 48 hours, more importantly I’ve put the smart meter in the cupboard 😂.

I can’t explain the small jump in temperature in the early hours on that day and it isn’t a common theme when I’ve checked other days. We do get the spike around dinner every day from the glazing at the rear. In mid October with outdoor temperatures around 14 degrees we were hitting 26 inside and very rarely dropped below 21. We don’t have an MVHR system.

I understand what you’re saying. I suppose it’s just taking some getting used to a different type of heating than we’ve used before and I’ll be happier with it when I’ve stopped constantly checking/tinkering with it. Im gonna run the manifold at 30 for the next 48 hours and leave all the stats on 19 and see if we can get a more stable temperature throughout the day, check the usage and go from there. I think that would benefit us most at weekends when we tend to be home all day. Thanks again for your input 👍

I did try turning the UFH mixer down to minimum (30) for a few hours but realise I wasn’t patient enough with it. After about 5 hours the floor didn’t feel like it had been on and I’d still clocked up about £7 in gas so I reverted back to 45. I’m a bit governed with the boiler flow because it still has to feed the rads upstairs so I think 45 is probably my limit, especially with these cold snaps but I’ll reduce UFH manifold to 30 and just leave all stats on 19 for a couple of days and check the usage again. I really need to stop doing my hourly check of the smart meter 😂. And yeah it’s definitely not because of lack of insulation, this is a typical day even when it was -4 outside. It boots in 3-5 and then usually sees us through until 3pm the next day. We’re up and out in a morning and only home 5pm’ish so it works for us. It’s south facing with lots of glass which is why we get a spike in temperature. Thanks for the reply 👍

Hi, A bit long winded but just looking for some advice. We’ve just moved into a house that we have renovated and just getting used to using UFH and trial and erroring boiler flow temps as well as adjusting the manifold temps and it just seems to be working out a lot more expensive to run the UFH side of the system than the CH side that feeds upstairs. Is this normal? If you see attached pics, (12-2pm) with boiler flow set to 55, ufh manifold temp set to 45, we always seem to consume roughly 44kw in a 2 hour period, is this normal? (it’s 7 loops all roughly 80m long). Compare this to central heating side (5 oversized rads and a towel rad) uses roughly 30kw over a 7 hour period. Once it gets to temperature it does hold there for hours which isn’t a bad thing. I’ve read about leaving it running all the time at say 19 degrees but the problem I’m having is it costs the initial heat up (it’s a screed floor) to start budging the thermostat and by the time it kicks back in, the floor slab is cold so you’re having to do the initial heat up all over again. Boiler is a baxi 830, 2 zones, UFH and CH, Floor build up is 150mm celotex with a 40-50mm liquid screed over it. Manifold pump is set to 2 and I have the salus auto balancing actuators. If that seems like normal operating costs then so be it but just looking for some reassurance that I’m not running it inefficiently. I’ve read about buffer tanks, short cycling etc.. Any ideas or advice appreciated

Very similar symptoms to my system before I realised the blending valve was the wrong way around (note the H and C on the pic). Worked fine for months surprisingly and then suddenly started locking the boiler out and just circulating water already in the system until I opened the valve fully. Probably isn’t your cause if you’re sure it’s been installed correctly but worth double checking. I swapped the valve around and it’s been fine since, although it’s annoying the temperature marking on the valve now faces the wall 😄.