Truanco heatpump setup?
Discussion
My brother has just had a Trianco Activair 15KW heatpump fitted under the ECO4 scheme.
He's trying to set it up (installers seemed clueless) with my help.
Unlike my Mitsubishi Ecodan heatpump, this Trianco seems to be trying to mimic an old gas boiler, with a simplified user interface, and more settings hidden away in "engineer's menus".
Figured out how to put it into weather compensation mode, and it's got 6 timers just like an older programmer, plus settings for flow and hot water target temps.
What we can't find is any way of controlling the hot water scheduling and reheat frequency. He only uses a couple of bowls of hot water each day, as they have a mains electric shower. Keeping the tank at a constant 50 degrees seems pointless.
I just have my Mitsubishi heat the hot water for an hour at night on cheap electricity, no reheating at all.
The whole installation goes totally against what Heat Geek say, with a big buffer, and microzoning via Radbot TRVs on all but one radiator.
Installers made no attempt to balance anything, all lockshields completely open. Left running in fixed flow temp mode.
It all works, but is wasting money, continually heating the hot water tank unless he turns everything off.
I assume this type of simplified setup is aimed at the ECO4 social housing sector?
My brother owns his house, but qualified as the state pension is now his only income.
He's trying to set it up (installers seemed clueless) with my help.
Unlike my Mitsubishi Ecodan heatpump, this Trianco seems to be trying to mimic an old gas boiler, with a simplified user interface, and more settings hidden away in "engineer's menus".
Figured out how to put it into weather compensation mode, and it's got 6 timers just like an older programmer, plus settings for flow and hot water target temps.
What we can't find is any way of controlling the hot water scheduling and reheat frequency. He only uses a couple of bowls of hot water each day, as they have a mains electric shower. Keeping the tank at a constant 50 degrees seems pointless.
I just have my Mitsubishi heat the hot water for an hour at night on cheap electricity, no reheating at all.
The whole installation goes totally against what Heat Geek say, with a big buffer, and microzoning via Radbot TRVs on all but one radiator.
Installers made no attempt to balance anything, all lockshields completely open. Left running in fixed flow temp mode.
It all works, but is wasting money, continually heating the hot water tank unless he turns everything off.
I assume this type of simplified setup is aimed at the ECO4 social housing sector?
My brother owns his house, but qualified as the state pension is now his only income.
It should not be 'continually heating the hot water tank'.
The HW tank should be well enough insulated that heat losses from it are not a big deal.
A modern tank should do better than 2kW per day, which is only costing you <1kWh of electricity.
The buffer tank is probably all about reducing short cycling, which can improve efficiency.
Balancing rads properly takes time, not surprised white van man didn't bother!
The HW tank should be well enough insulated that heat losses from it are not a big deal.
A modern tank should do better than 2kW per day, which is only costing you <1kWh of electricity.
The buffer tank is probably all about reducing short cycling, which can improve efficiency.
Balancing rads properly takes time, not surprised white van man didn't bother!
It's reheating every hour or so, presumably because the tank temperature has dropped low enough to overcome the hysteresis of the sensor logic. Could be heat loss, or maybe "destratification" as the temp equalises?
My tank loses about 9 degrees in 24 hours, but the Mitsubishi controller can be set to a DHW scheduled time and duration, as well as the option to reheat after a user-defined temperature drop.
Trianco seems to have none of this.
My tank loses about 9 degrees in 24 hours, but the Mitsubishi controller can be set to a DHW scheduled time and duration, as well as the option to reheat after a user-defined temperature drop.
Trianco seems to have none of this.
It is what it is.
Give people subsidised stuff they just complain.
People mostly want hot water morning and evening.
If it's not doing their morning shower then it's mostly evenings.
If you want your HW to be at 60degC when you need it to wash up after dinner, then it's perhaps more efficient to heat it to 60 all day than to heat it to 67 so it cools to 60 when you want it?
Stuff with complex controls has a high cost in callouts when the public get near it.
Also bear in mind it's not 1970 any more, cheap rate power at night is not a given looking forwards.
Personally I would want to know what the HW is costing per day.
Possibly money could be saved by using tank water for the shower?
Give people subsidised stuff they just complain.
People mostly want hot water morning and evening.
If it's not doing their morning shower then it's mostly evenings.
If you want your HW to be at 60degC when you need it to wash up after dinner, then it's perhaps more efficient to heat it to 60 all day than to heat it to 67 so it cools to 60 when you want it?
Stuff with complex controls has a high cost in callouts when the public get near it.
Also bear in mind it's not 1970 any more, cheap rate power at night is not a given looking forwards.
Personally I would want to know what the HW is costing per day.
Possibly money could be saved by using tank water for the shower?
He was supposed to be having it done by Octopus, cost to him of around £3k. All the kit was delivered, installers turned up, and said it wouldn't work, left site.
He contacted several other suppliers, and one suggested ECO4, free. Too good to turn down. He retired 8 months ago now living on just the state pension. Got taken to the cleaners by his ex, had to cash in everything to buy her out of the house.
He's very grateful to now have wirking central heating, and the refund from Octopus. He's had no central heating for 3 years since his LPG boiler died.
We are just trying to get it working economically.
Anyway, it seems like Trianco heatpumps are designed, as you say, to work just like boilers, with not user interference. There is no facility to schedule the DHW.
I've been told that there is the option to add an external third party programmer though - 2 wires, volt-free relay. Should be simple enough if we can access the wiring centre.
He contacted several other suppliers, and one suggested ECO4, free. Too good to turn down. He retired 8 months ago now living on just the state pension. Got taken to the cleaners by his ex, had to cash in everything to buy her out of the house.
He's very grateful to now have wirking central heating, and the refund from Octopus. He's had no central heating for 3 years since his LPG boiler died.
We are just trying to get it working economically.
Anyway, it seems like Trianco heatpumps are designed, as you say, to work just like boilers, with not user interference. There is no facility to schedule the DHW.
I've been told that there is the option to add an external third party programmer though - 2 wires, volt-free relay. Should be simple enough if we can access the wiring centre.
Lot more information needed.
Ie which model, and more importantly the precise way it has been installed.
Is it one of these?:
https://trianco.co.uk/wp-content/uploads/2025/05/A...
It's quite possible the installation is the problem.
If there is a buffer tank then the heat pump should not be in a "fixed outlet temperature" mode.
caziques said:
Lot more information needed.
Ie which model, and more importantly the precise way it has been installed.
Is it one of these?:
https://trianco.co.uk/wp-content/uploads/2025/05/A...
It's quite possible the installation is the problem.
If there is a buffer tank then the heat pump should not be in a "fixed outlet temperature" mode.
Pretty sure it is the model in your link, going by what my brother described.Ie which model, and more importantly the precise way it has been installed.
Is it one of these?:
https://trianco.co.uk/wp-content/uploads/2025/05/A...
It's quite possible the installation is the problem.
If there is a buffer tank then the heat pump should not be in a "fixed outlet temperature" mode.
I should be seeing him on Thursday, will try and figure out how they have installed it.
Odd that the manual shows an installation method with no sensor in the DHW tank.
Not tried the app yet.
dhutch said:
OutInTheShed said:
The HW tank should be well enough insulated that heat losses from it are not a big deal.
This. Our 250l boggo OSO tank is something like 60w standing losses, so even on resistive electrical heating at 25p/unit its 35p a day
Just let it keep the hot water tank hot.
The issue is the energy wasted in the heatpump and the pipework (along the wall and up a floor outside) every time it starts up, especially if it starts up just to heat the tank (no heating demand).
Still not a huge amount of money, but it adds up. He's trying to live on less than a grand a month.
clockworks said:
The actual heatloss (and therefore the energy required to bring it back up to target) is going to be the same whether it's heated once a day, or topped up every hour or so.
The issue is the energy wasted in the heatpump and the pipework (along the wall and up a floor outside) every time it starts up, especially if it starts up just to heat the tank (no heating demand).
Still not a huge amount of money, but it adds up. He's trying to live on less than a grand a month.
Ok. Yeah I get that short cycling the heatpump its not ideal. The issue is the energy wasted in the heatpump and the pipework (along the wall and up a floor outside) every time it starts up, especially if it starts up just to heat the tank (no heating demand).
Still not a huge amount of money, but it adds up. He's trying to live on less than a grand a month.
I thought you where trying to avoid heating the full volume of water, in order to reduce standing losses.
dhutch said:
Ok. Yeah I get that short cycling the heatpump its not ideal.
I thought you where trying to avoid heating the full volume of water, in order to reduce standing losses.
Ah right.I thought you where trying to avoid heating the full volume of water, in order to reduce standing losses.
No, just heat it once a day, up to 45 or so, during the tariff cheap period. That'll cost 10p a day.
It's currently costing a lot more.
He's actually been without on demand hot water for about 3 years since his LPG boiler died, boiling a kettle to wash up, and an electric shower.
He was using fan heaters and oil filled radiators, costing a tenner a day for one room at a time.
Whatever happens, the heatpump will be cheaper, but he's only just retired. Big drop in income.
dhutch said:
OutInTheShed said:
The HW tank should be well enough insulated that heat losses from it are not a big deal.
This. Our 250l boggo OSO tank is something like 60w standing losses, so even on resistive electrical heating at 25p/unit its 35p a day
Just let it keep the hot water tank hot.
Someone not using the HW for baths or showers probably gets no value from heating the whole tank.
Heat pumps are not in their best use-case, heating a water tank to 'kill the legionella' temperature.
If he's on some kind of E7 type tariff, just turn down the heat pump systems HW target temp and put the immersion on a timer.
Set the immersion 'stat to 65 or so.
And buy another jacket for the cylinder...
Lag all the HW pipes.
Or just turn off the HW and get a boiling water tap for the kitchen.
The electric shower can be a big slice of an electricity bill.
We had one, it made a difference when we no longer got up for work early enough to shower with E7.
OutInTheShed said:
There is a case for just using an immersion heater. It is simple and doesn't cost much if the tank is properly insulated.
Someone not using the HW for baths or showers probably gets no value from heating the whole tank.
Heat pumps are not in their best use-case, heating a water tank to 'kill the legionella' temperature.
If he's on some kind of E7 type tariff, just turn down the heat pump systems HW target temp and put the immersion on a timer.
Set the immersion 'stat to 65 or so.
And buy another jacket for the cylinder...
Lag all the HW pipes.
Or just turn off the HW and get a boiling water tap for the kitchen.
The electric shower can be a big slice of an electricity bill.
We had one, it made a difference when we no longer got up for work early enough to shower with E7.
He's going to see how low he can set the HW target temperature. Someone not using the HW for baths or showers probably gets no value from heating the whole tank.
Heat pumps are not in their best use-case, heating a water tank to 'kill the legionella' temperature.
If he's on some kind of E7 type tariff, just turn down the heat pump systems HW target temp and put the immersion on a timer.
Set the immersion 'stat to 65 or so.
And buy another jacket for the cylinder...
Lag all the HW pipes.
Or just turn off the HW and get a boiling water tap for the kitchen.
The electric shower can be a big slice of an electricity bill.
We had one, it made a difference when we no longer got up for work early enough to shower with E7.
I used to have an oil boiler which was plumbed for heat only, so HW was done with an immersion heater. It used about 1.75KWh, running once a day. 3KW for 35 mins.
The heatpump uses 0.8 KWh per day, outside the heating season.
Daily electric shower, uses about the same (10KW shower running for 5 minutes), but obviously not at the off-peak rate.
Unfortunately we had the bathroom completely redone, with a new electric shower, before thinking about switching to a heatpump.
clockworks said:
He's going to see how low he can set the HW target temperature.
I used to have an oil boiler which was plumbed for heat only, so HW was done with an immersion heater. It used about 1.75KWh, running once a day. 3KW for 35 mins.
The heatpump uses 0.8 KWh per day, outside the heating season.
Daily electric shower, uses about the same (10KW shower running for 5 minutes), but obviously not at the off-peak rate.
Unfortunately we had the bathroom completely redone, with a new electric shower, before thinking about switching to a heatpump.
Did you have a new, better insulated tank with your heat pump?I used to have an oil boiler which was plumbed for heat only, so HW was done with an immersion heater. It used about 1.75KWh, running once a day. 3KW for 35 mins.
The heatpump uses 0.8 KWh per day, outside the heating season.
Daily electric shower, uses about the same (10KW shower running for 5 minutes), but obviously not at the off-peak rate.
Unfortunately we had the bathroom completely redone, with a new electric shower, before thinking about switching to a heatpump.
Some solar panels to power the immersion might be an idea, but if the immersion is only costing 40p a day, payback is going to be a long time.
Some people however, use crazy amounts of hot water.
I've found it good to have at least one simple electric shower in the house when heating systems play up.
OutInTheShed said:
Did you have a new, better insulated tank with your heat pump?
Some solar panels to power the immersion might be an idea, but if the immersion is only costing 40p a day, payback is going to be a long time.
Some people however, use crazy amounts of hot water.
I've found it good to have at least one simple electric shower in the house when heating systems play up.
Yes, went from an old vented immersion tank with a jacket, to a fancy new unvented setup.Some solar panels to power the immersion might be an idea, but if the immersion is only costing 40p a day, payback is going to be a long time.
Some people however, use crazy amounts of hot water.
I've found it good to have at least one simple electric shower in the house when heating systems play up.
Like my brother, we really only use the DHW for washing up and hand washing. He's going to get a small solar setup installed as part of the ECO4 deal - 6 panels.
I don't currently have solar, but am considering it. Possibly batteries. RoI numbers don't really seem to add up though.
For one person, the savings using a heat pump to heat the water bear no comparison to the installation cost.
Three people in a house and the economics start to work.
There must be a way to "disable" the hot water heating, then the heat pump controls for heating can be considered.
One of the main problems is overcontrol, particularly when there is a large heat pump doing radiators without a buffer tank. For example, a 15kW unit that can run at 7.5 kw, will have an issue when too many radiators are switched off.
With a fixed output temperature, the unit would be constantly stopping and starting - very wasteful.
https://renewableheatinghub.co.uk/forums/renewable...
I would recommend posting in the above, as a collection of experts who might be able to help.
Who were the installers? What is the complains procedure of the Grant he claimed via?
I would recommend posting in the above, as a collection of experts who might be able to help.
Who were the installers? What is the complains procedure of the Grant he claimed via?
Andeh1 said:
https://renewableheatinghub.co.uk/forums/renewable...
I would recommend posting in the above, as a collection of experts who might be able to help.
Who were the installers? What is the complains procedure of the Grant he claimed via?
I'm pretty sure everything is working as expected, it's just limitations of the hardware and the way ECO4 installations are done:I would recommend posting in the above, as a collection of experts who might be able to help.
Who were the installers? What is the complains procedure of the Grant he claimed via?
Simple controls that mimic a gas boiler for the end user
Big buffer tank so that there's no problems when the TRVs all close down
No real thought given to economy, because it was a free install, and most systems will be in rented properties.
Although it would be nice to have more control (to improve economy), it will be cheaper to run than his old bottled LPG boiler, and much cheaper than the electric heaters he's been using for 3 years since the boiler died.
Seems like the only issue was with the final commissioning and handover, but that happens with a lot of ASHP installs.
I'm going round later with my digital temperature thingamajig and thermal imaging camera to have a go at balancing, and a couple of Tapo temperature sensors so he can log room temps over time.
We'll also check out how it's all connected up, and work out if a third party programmer can be fitted for DHW.
If there are any problems, I'll get him to try the renewable heating forum - I got some great advice on there for my Mitsubishi ASHP setup.
caziques said:
One of the main problems is overcontrol, particularly when there is a large heat pump doing radiators without a buffer tank. For example, a 15kW unit that can run at 7.5 kw, will have an issue when too many radiators are switched off.
With a fixed output temperature, the unit would be constantly stopping and starting - very wasteful.
Similar issue with excessive 'control' and zoning even with gas boilers, you very quickly get to a point where you are hampering the all important available 'emitter' size, without materially reducing the total amount of heat needed (because it gets to the turned off zones anyway, through the walls, ceiling and under doors etc) and hence you reduce the system efficiency. This is only more so with heatpumps than gas boilers.With a fixed output temperature, the unit would be constantly stopping and starting - very wasteful.
The OP references 'Heat Geeks' early on, who are strong advocates against zoning and powered trv's for the above reasons.
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