How Does My Boiler Work?

[denso13]

It doesn't programme ons and offs, but temperatures.

You can set temperatures and time periods.

 

[old duffer]

I had expected the heating engineers to know all of this...with variable speed pumps=variable pump flow rates=variable pump HP etc etc. Seems odd that it being around for a number of years now, the heating engineers don't seem to know about it. It works on the differential temperature between the flow and return from the boiler.

 

[old duffer]

This is a simple to understand interactive diagram. Hope it helps the professional heating engineers as well...https://heatpumps.co.uk/heating-simulator-for-radiators/

 

[DIYWell]

You can set temperatures and time periods.

I read the instruction leaflet. There's no mention of "off" for the new controller.

 

[DIYWell]

Then you wouldn't put the stat in the lounge. Systems need designed properly with correctly sized radiators in each room and the stat fitted in the correct place.

I would tend to agree. However, finding a heating engineer who does the analysis and arithmatic doesn't happen. It's always "this looks like it needs ..." based on their previous experiences.

And modern roomstats are wireless so can't be fitted in the right place. The occupants just wonder about with them.

 

[Harry Bloomfield]

I read the instruction leaflet. There's no mention of "off" for the new controller.

Setting a low temperature for a period, is the same as 'off'.

 

[ericmark]

I would think different makes of boiler will have different methods, but the old method was for boiler to include some anti-cycle software, so once it can't modulate any more it switches off for a time, one the time has elapsed it turns back on, if it returns hot water quickly it assumes it was not needed and increases the off time, and if it takes a long time then the time is decreased.

The problem is although it will not fire for long it will never stop firing up, and it needs TRV's fitted to all radiators even one without can result in the anti cycle software not working.

The problem is finding out exactly how the actual boiler fitted works, having a towel rail with no TRV may mess up the system, but it may not, and there is very little information as to how each make of boiler works.

So the idea is to select an area to work a wall thermostat, the original idea was a room with no outside doors, and no alternative heating including sun light through windows normally kept cool so on warm days it will turn off the system, and that room would not have a TRV. However in real terms such a room rarely exists.

Using the hall has a problem as when the front door is opened you want fast recovery, so it needs a TRV and wall thermostat carefully set so after door is opened the TRV will reheat hall fast, but reduce the rate before it gets warm enough to turn off wall thermostat, so it will only turn off wall thermostat on warm days. I did this with mothers house so can say it does work, however it took some time to adjust to work well. And if you want as I did varying temperatures through the day you need both the wall thermostat and TRV to be programmable.

The boilers I have had did not have option to use a modulating wall thermostat, and when I tried to use same system as mothers house in this house, it failed to work as well as the hall cools too slow.

It seems Nest Gen 3 in USA have extra temperature sensors that you can place in other rooms to main thermostat so if a room cools it will trigger the boiler, however seems not released in UK. When Hive first came out it also only worked in one room, but then linked TRV heads were released, Drayton Wiser, Honeywell EvoHome and others also link TRV heads to wall thermostat, EPH is designed to work as Master/Slave with motorised valves and still use OpenTherm control onto the Ebus.

But the problem is cost, some of the systems can cost £1000 to control the heating, so most systems use some form of compromise.

We want the modulating boiler to turn off when running cool, as then less heat lost out of flue when it turns off, and so the less times the on/off wall thermostat operates the better, we want the TRV to do most of the controlling unless using a modulating wall thermostat rather than on/off.

However information as to how much heat is lost out of flue with each control system seems lacking, and it must change home to home, I set mothers house to cool to 16°C over night, however it was too well insulated so never dropped below 17°C, and reheating the anti-hysteresis software in the TRV was OTT, so had to set heating to 22°C for an hour then back to 20°C and I am not convinced saved much energy by cooling overnight.

But having the radiators run cooler helped when sun came through bay window as they could cool completely quicker. So allowing the boiler to modulate also means better control to on/off.

Working out best method also needs radiators large enough, theory is using programmable TRV heads you can heat up the home room at a time, allowing faster recovery, but in real terms at least in this house the radiators are too small, so even when stinking hot it takes nearly two hours to reheat a room. Which means geofencing simply does not work.

 

[Harry Bloomfield]

So the idea is to select an area to work a wall thermostat, the original idea was a room with no outside doors, and no alternative heating including sun light through windows normally kept cool so on warm days it will turn off the system, and that room would not have a TRV. However in real terms such a room rarely exists.

Using the hall has a problem as when the front door is opened you want fast recovery, so it needs a TRV and wall thermostat carefully set so after door is opened the TRV will reheat hall fast, but reduce the rate before it gets warm enough to turn off wall thermostat, so it will only turn off wall thermostat on warm days. I did this with mothers house so can say it does work, however it took some time to adjust to work well. And if you want as I did varying temperatures through the day you need both the wall thermostat and TRV to be programmable.

The hall was were I installed my original wired stat, followed by the default position for the wireless one, then the more sophisticated 407F and is the one radiator without a TRV. We don't habitually use the front door, rather we tend to use the side door. Doors internally tend to be almost always open. A negative of having it there, is that when ever she begins serious cooking, then the heat from the kitchen gets into the hall, which then stops the heating for the rest of the house. When she cooks and if it happens to be cold, I unclip the 407F from its bracket in the hall and move it to the living room.

The stat should always be installed on an inside wall, because the inside walls tend to be more representative of temperature, than an outside wall, where it will feel the cold from the outside. I originally wired mine to the wall separating the hall from the living room - with the wire to both sides of the wall, so I could have the stat in the hall or the living room.

 

[bernardgreen]

How did my generation survive childhood without all this high tech over complicated controls.

OK so we woke up some days in winter with ice on the inside of the window panes. Blankets and appropriate clothing kept us warm and safe.

A simple system of heating was a major benefit.

Are today's intelligent systems really a benefit to anyone other than the manufacturers and their shareholders

 

[ericmark]

When I was a lad only one house I visited had central heating, I remember going into the cellar to see the boiler with the hopper feed for solid fuel.

We had it at school, old Lancaster boiler but not allowed to actually boil, it was not until I married I had a house with central heating, and it was a real problem during the Winter of Discontent and decided never again would I rely on electric for heating. So next house had flue brick and a gas fire, this house a full hearth and open fire, so with no electric we can still heat the house.

Never lit fire here, but gas fire was used a lot, no need for geofencing with a Myson fan assisted radiator plus large standard radiator and a gas fire at 4.5 kW living room heated up fast.

However the Myson fan assisted was very good with the old non modulating gas boiler, but there is a problem with new boiler as it returns the water too hot and can turn down boiler, one in the house as kick space heater is OK, but as the number increases then it can mess up the system.

Are today's intelligent systems really a benefit to anyone other than the manufacturers and their shareholders

The reason for the complex system is in the main so it can work within the regulations. It is not a case of people wanting the system but it being forced upon them. Also there is some misinterpretation of what the regulations say, reading internet pages published by local authorises it seems a TRV is seen as a zone valve, there is no need for motorised valves splitting upper and lower floors, all they do is make control harder, the Drayton Wiser wall thermostat and TRV system is designed to work with a single channel, as are most, so first thing one needs to do it increase control is rip out the zone valves, there is one EPH which will work with zone valves, but it is an either/or either zone valves or TRV's not both.

And as I have found to my cost, manufacturers change their mind, so I got Energenie Mihome TRV heads that claimed to work with Nest, then I got Nest Gen 3, only to find after google took over Nest the support for Energenie was removed, so until those sensors

are made available in the UK my heating can fail to get some rooms warm enough. hind sight would have been better with cheaper Hive, specially as my oil boiler does not modulate and is never going to be OpenTherm enabled.

 

[mcmoby69]

Weather comp, In really cold weather put a jumper on and save the planet.

The Germans seem to cope ok.