Efficient use of boiler.

Calibos

We've a Baxi Megaflow 28HE ie boiler with 3 zones on Myson valves. Hot water, downstairs and upstairs. 16 rads in total. 2 of which are bathroom with regular lock shield valves and 14 with TRV's. Sunvic Timer controller but no central thermostat controller for setting a temperature.

There is always several people in the house and there is always some people upstairs and some downstairs so the upstairs/downstairs zoning is moot. Both zones always turned on or off at the same time.

Up to now I haven't been able to get it into the heads of.people that the TRV's are not a heat up faster or slower device, that's the boiler temp setting. They are the temperature the rad will switch off at when its reached. I may have finally gotten it through to them though.

We've always had the boiler come on at 6am say, go off at 11am and come back on at 4pm and off again at 10pm with all TRVs at setting 5 because they buggers would keep turning them back to 5 no matter what I did or said.

If I have successfully convinced them to leave the TRV's at a comfortable 21deg setting 3 but I set a single timer for all zones of 6am-10pm with the TrVs coming on and off to maintain the 21deg all day, do you think I'll end up saving a few quid while maintaining a comfortable temp all, neutral cost/bill implication but maintaining comfort or can I expect higher bills but maintaining comfort. Implication 1 or 2 is fine but I'd prefer a bit of discomfort to increased bills.


[EDIT - Corrected Model number/Kilowatt of boiler]

Dtp1979

Calibos wrote: »

We've a Baxi 36HE boiler with 3 zones on Myson valves. Hot water, downstairs and upstairs. 16 rads in total. 2 of which are bathroom with regular lock shield valves and 14 with TRV's. Sunvic Timer controller but no central thermostat controller for setting a temperature.

There is always several people in the house and there is always some people upstairs and some downstairs so the upstairs/downstairs zoning is moot. Both zones always turned on or off at the same time.

Up to now I haven't been able to get it into the heads of.people that the TRV's are not a heat up faster or slower device, that's the boiler temp setting. They are the temperature the rad will switch off at when its reached. I may have finally gotten it through to them though.

We've always had the boiler come on at 6am say, go off at 11am and come back on at 4pm and off again at 10pm with all TRVs at setting 5 because they buggers would keep turning them back to 5 no matter what I did or said.

If I have successfully convinced them to leave the TRV's at a comfortable 21deg setting 3 but I set a single timer for all zones of 6am-10pm with the TrVs coming on and off to maintain the 21deg all day, do you think I'll end up saving a few quid while maintaining a comfortable temp all, neutral cost/bill implication but maintaining comfort or can I expect higher bills but maintaining comfort. Implication 1 or 2 is fine but I'd prefer a bit of discomfort to increased bills.

If you're worrying about efficiency, I'd be more concerned that you've a 36kw boiler heating 16 rads. Unless your house is huge with big big rads, why was such a boiler installed?

The Sidewards Man

Dtp1979 wrote: »

If you're worrying about efficiency, I'd be more concerned that you've a 36kw boiler heating 16 rads. Unless your house is huge with big big rads, why was such a boiler installed?

Why do you always quote the op?


MOD:Careful now or your going to get yourself in to trouble, if you could keep your posts relevant to the topic at hand that would be nice.

Dtp1979

The Sidewards Man wrote: »

Why do you always quote the op?

Go away troll

roy rodgers

Well I have a my down to 12 kw doing a 1800sq ft house. And even at that it's slightly over sized when I'm running the speratate zones.

Anyways op you should put a central room stat in for each zone and that would make the zones even more efficient. I find trvs can vary from room to room. Some rooms will need to be set at 2 and other at 4 to maintain an even temperature..
I have a wife and a 4 month child and she insists on have the red light on the programmer all day and all night!!! But she doesn't know about the room stats how they work. So they are set at 19 degrees and the house is always warm enough and the gas bill is very reasonable around 70 euro a month.
If your getting room stats get the ditital ones as they are more accurate than your standard ones

Wearb

roy rodgers wrote: »

Well I have a my down to 12 kw doing a 1800sq ft house. And even at that it's slightly over sized when I'm running the speratate zones.

Anyways op you should put a central room stat in for each zone and that would make the zones even more efficient. I find trvs can vary from room to room. Some rooms will need to be set at 2 and other at 4 to maintain an even temperature..
I have a wife and a 4 month child and she insists on have the red light on the programmer all day and all night!!! But she doesn't know about the room stats how they work. So they are set at 19 degrees and the house is always warm enough and the gas bill is very reasonable around 70 euro a month.
If your getting room stats get the ditital ones as they are more accurate than your standard ones

+1 on stat (with boiler interlock) needed for each zone, incl DHW. Remove (or lock at highest setting) TRVs in room where stat needs to be located.

Remember that TRVs can only control the heat for the room they are in if that door is closed.

Calibos

Dtp1979 wrote: »

If you're worrying about efficiency, I'd be more concerned that you've a 36kw boiler heating 16 rads. Unless your house is huge with big big rads, why was such a boiler installed?

Dunno where I got the 36 from. Must have read a thread from someone with one and the number stuck in my head for some reason. Just checked and its a Baxi Megaflow 28HE IE. House is approx 2400sqft.

Basically, one can think of the house as a single zone for all intents and purposes because there is always some people downstairs and some people upstairs all through the day. The house is never empty either. It is NOT the usual scenario of mom and dad and kids all at work/school for half the day with the house empty but even when everyone is back home no one upstairs till bedtime. If its cold enough to need the heating on then it needs to be on in the whole house at the same time as more often than not theres at least one or two people both upstairs and downstairs at any given time. We have zoned heating but our life/work styles means the zoning is moot certainly while we are living here.

My thinking is that setting all the rad TRV's to achieve a comfortable 21ºc with the heating on a single 6am-10pm timer might be more akin to the operation of underfloor heating where its actually wrong to have the system going on and off all day, but with our TRV's reacting quicker and topping up the heat right where its needed when an outside door or window is opened. I'm getting arguments back from family that the bills will be massive because of the all day timer setting but I'm trying to explain to them that the TRV's shut off when the room is up to temp and thus the boiler doesn't waste hot water on that room regardless of whether the timer is on all day or not. Trying to explain to them that their counter arguments about higher temps outside and wasting heat is wrong too. If a warm front moves in and ambient rises, the house won't lose heat as fast nor will the boiler have to work as much to close the smaller temp gap between ambient and 21º.

My position (Open to correction which is the purpose of this thread) is that if the family can be persuaded to trust the TRV's and just leave them alone and with an all day 6am-10pm timer set during cold weather, that worst case is cost neutral but in return we get whole house comfort with no one needing to to and fro turning up and down TRV's and turning on and off heating or boosting or messing with timers which is the case now.

Roll on the likes of the Honeywell systems competition bring down prices in the next few years for accurate temp Wifi enabled and app controllable electronic TRV's. Best of all worlds by the sounds of it.

Wearb

It's not going to be cheap keeping all that area at 21° all that time. Usually when people are up and moving about, a temp of less than 21° is comfortable. Then later when everyone settles down to watch TV or whatever, 21° might be needed.

To meet the needs that you described, I would use a stat with setback timer with boiler interlock in the living area. That way you could have a lower temp during active periods.

The way you have described, never turns off the boiler during your set time. This means that even when all the TRVs close, the boiler will still cycle to keep itself up to its set temperature.

Calibos

Ah OK.

So maybe just proceed with the current timer settings for another Winter and seeing as I'd be thinking about the likes of the Honeywell Evohome next year not bother with a stat with setback timer etc this year. At least I've achieved something which was to finally convince people that setting 5 on a TRV does not mean quicker heat it means a hotter room.

Wearb

If you do not want to invest, because you are waiting for a more modern solution, then the timer and trv's will be best option that you have. I would certainly consider turning back the trv temperatures in the bedrooms. Unless they are being used as living areas, to 16° or 17°

Calibos

Wearb wrote: »

If you do not want to invest, because you are waiting for a more modern solution, then the timer and trv's will be best option that you have. I would certainly consider turning back the trv temperatures in the bedrooms. Unless they are being used as living areas, to 16° or 17°

Thats the thing. They are being used as living areas. Everyone has their own TV's and computers and sound systems in their rooms. Don't get me wrong, the whole family spend time together chatting in communal areas too, be it meals, watching a movie together on the projector in the Livingroom, just having a chat etc but all will retire to own 'bedsits' at various points of the day when not at work so theres always at least one person on any given floor at any given time really. Eventually with Wifi TRV's we'll be able to programme a timer for every room individually based on their work shifts. That said, I watched a 1.5 hour youtube vid about setup and install of Evohome and in the comment section he posted that his bills were higher Winter 2014/15 than 2013/14. Dunno if he correlated that fact with the Weaather records though. Might have been a colder Winter that masked any savings.

Wearb

Individual room control is the way to go, but it will only work well with closed doors. Ideally such systems should be designed for at plumbing stage to prevent boiler cycling when only one room is calling for heat.
With the amount of insulation in new houses, all this tight control might not be as important. So a payback time should be considered.

ted1

This is why I'm not a fan of TRVs, a good programmable stat is in my opinion much better. For sleeping you only should have the gearibg at a about 16 deg.
Having a constant temp and the boiler on a timer makes no sense. Ideally you would have your boiler set to come I when required and vary the temps throughout the day