Remote control of boiler flow temperature?

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I'm looking into a new regular boiler, or maybe a system boiler.

I'm a bit hopeless with tech. Is there an app, or smart controller, which lets you remotely alter the boiler flow temperature? Reason is, I might want to run the CH very cool, but be able to boost the temperature for DHW. It's a bit clunky, but I envisage turning DHW on for an hour a day and turning CH off. But, I wouldn't want to have to go into the garage and change the temperature manually every time.

Are there better ways to do this? I've mainly been looking at Worcester Bosch. They have an option for a "diverter valve" on the system boilers. Does anyone know if this lets you have the CH and DHW at different temperatures? Any other options?
 
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Just been looking at exactly the same thing.

At the moment there doesn't seem to be a simple way to implement this though an Open Therm (OT) enabled boiler and control is the easiest direction to head in. I am still working down through a load of information though to understand what may be the easiest way to do this.
 
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You might need something like a priority hot water arrangement, which might be what Worcester are referring to.
 
This can certainly be achieved with an OpenTherm capable boiler (not WB) set up for Priority Hot Water. My preference for this arrangement is the Intergas Xclusive but others can do it too. WB can do it with their internal diverter but you have to buy their own very expensive controls.
 
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You might need something like a priority hot water arrangement, which might be what Worcester are referring to.
WB's diverter valve option is exactly that, it performs as a HW priority and the EMS can then raise the setpoint but the issue with that is it then disables the CH, so if you need to run the HW to recover say a full cylinder, then the CH could cool down significantly until the HW is satisfied .

I'm looking at controls that will allow the system to adjust the boiler's setpoint temp depending on what is being called for, which seems like a really easy requirement but the controls/software don't seem to be enabled to do it.

In essence what I'm looking to implement is - when a programmer calls for CH the smart control via OT runs the boiler setpoint @ 50deg, the HW demand kicks in, then the OT controls raise the set point to ~ 60Deg, HW satisfied, drop it back to 50Deg but have it in a mid position/dual demand configuration.

At the moment it seems to need separate valves and sensors but that is overly complicated and introduces multiple failure points
 
I read about some sort of third party converter to let WB use OpenTherm, but I would be worried about it not being kept updated. Are WB the only major manufacturer who don't join in with OT?
 
No, Vaillant/Glowworm don’t either. Not sure about some others, I believe Baxi, Intergas, Ideal support OT.
 
I might have come across something tangentially yesterday, but I don't understand it really. It was mentioned that the EPH Combi pack might do this. Here on pages 38-41. But, as I say, I don't understand it.

Looked at that and for a sec I though the same but that's for a combi boiler and that controls the DHW output of the boiler over OT (remote) , not to control a separate flow set point for a cylinder.
 
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I read about some sort of third party converter to let WB use OpenTherm, but I would be worried about it not being kept updated. Are WB the only major manufacturer who don't join in with OT?
WB introduced their own protocol called EMS, it's basically the same but it isn't open source so only WB use it with their own controls.

OT is used by a number of others but it's the separate Set Points just over OT without other additional controls, stats, etc that seems to be the issue.
 
Looked at that and for a sec I though the same but that's for a combi boiler and that controls the DHW output of the boiler over OT (remote) , not to control a separate flow set point for a cylinder.
That makes sense now.
 
EPH controls can do it with a simple S plan (up to 5 zones). I have it with 2 heating and a HW with Vokera's Vision Plus system boiler although it will work with our heat only boiler or any other boiler in our ranges with OpenTherm.
Alternatives are to chose a boiler where max and min can be selected in parameters. If you want more than that you can fit an accessory box to arrange say radiator temps, underfloor temps with an electronic mixing valve (better than thermostatic).

Alternatively if you are preparing and will wait till end of year look for the Vibe Max S system boiler with wi-fi smart key, flow temps adjustable from app. Available November
 
WB's diverter valve option is exactly that, it performs as a HW priority and the EMS can then raise the setpoint but the issue with that is it then disables the CH, so if you need to run the HW to recover say a full cylinder, then the CH could cool down significantly until the HW is satisfied .

I'm looking at controls that will allow the system to adjust the boiler's setpoint temp depending on what is being called for, which seems like a really easy requirement but the controls/software don't seem to be enabled to do it.

In essence what I'm looking to implement is - when a programmer calls for CH the smart control via OT runs the boiler setpoint @ 50deg, the HW demand kicks in, then the OT controls raise the set point to ~ 60Deg, HW satisfied, drop it back to 50Deg but have it in a mid position/dual demand configuration.

At the moment it seems to need separate valves and sensors but that is overly complicated and introduces multiple failure points
The whole point is that the CH doesn't cool down significantly while heating the cylinder. A reheat on a cylinder using hot water priority should take around 10-15 minutes, during which time you'll notice almost zero difference in the room temperature. A mid position valve would just result in the radiators getting too hot and the reheat time of the cylinder significantly increasing
 
The Urban Plumber has a useful video on how to setup a hot water priority system where the boiler runs water at maximum output to heat water in the cylinder, but will operate the central heating at a lower flow temp with OpenTherm & weather compensation for efficiency.

 
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