Completely new heating install, best way to configure for EvoHome?

[JohnDoe]

@John Doe. Nest 3 is an option but so are 3 Evohome controllers. There isn't much difference in price. The Evohome controller has a built in sensor so it will work in a zone with no HR92s or in a zone with HR92s.

I think I would need 3 x Nest 3rd gen at 200 each so that would be 600 inc vat and that would be it?

Do I not need HR92s in the location where the EvoHome controller is sited?

[HenGus]

Do I not need HR92s in the location where the EvoHome controller is sited?

If you are happy to have manual TRVs in one zone (say a floor of your house) then you don't need HR92s. Just use Evohome in a single zone mode as you would a thermostat and timer. This would work in the scenario described in your original post.

[JohnDoe]

In addition to my previous long post (above), reading about signal issues.. my boiler and tank are in the cellar. This has little to zero mobile phone reception, however, the internet connection will come into here and then be distributed to the rest of the house by CAT6 and/or wireless repeaters, as required.

Looking over the EvoHome literature, the hot water kit will obviously be sited at the cyliner (in the cellar) as well as the wireless relay box. Can the wireless relay box be extended(?) as if it has to remain in close proximity to the boiler, I doubt anything will be able to wirelessly communicate with it.

[HenGus]

In addition to my previous long post (above), reading about signal issues.. my boiler and tank are in the cellar. This has little to zero mobile phone reception, however, the internet connection will come into here and then be distributed to the rest of the house by CAT6 and/or wireless repeaters, as required.

Looking over the EvoHome literature, the hot water kit will obviously be sited at the cyliner (in the cellar) as well as the wireless relay box. Can the wireless relay box be extended(?) as if it has to remain in close proximity to the boiler, I doubt anything will be able to wirelessly communicate with it.

The BDR91 works in the 868MHz wifi band. It talks to the controller (in my situation) and the Controller is wired to the boiler. If you wanted to site the 3 BDRs next to the boiler then, in theory, they should have the same range as the HR92s.

The Evohome Shop does offer a wifi test kit.

https://theevohomeshop.co.uk/en/honeywell-evohome/65-honeywell-evohome-wireless-signal-test-kit.html

[DBMandrake]

If you are happy to have manual TRVs in one zone (say a floor of your house) then you don't need HR92s. Just use Evohome in a single zone mode as you would a thermostat and timer.

You keep suggesting this in various threads (at least I think it was you in the other threads) but this will not work.

The only time you can use the Evotouch's built in sensor without an actuator for the zone is when the whole system is configured for only a single zone. In this case you have only a boiler relay and it emulates a typical single wall stat system which only controls the boiler.

However as soon as you have two or more zones you cannot do this. You MUST have an actuator for the zone - either an HR92, BDR91 (with a zone valve that controls only the radiators in that one room, not a general CH zone valve that controls all zones) or an underfloor heating zone.

You can't just use the built in temperature sensor with no actuator in a multi-zone configuration, believe me I tried, back when I was first building up my system and only had one HR92, and I had nothing but trouble with comms faults as the only way to trick the system into doing what you suggest is to double bind the boiler relay - NOT a good idea. Both Honeywell and Richard at the evohomeshop advised me that this configuration is not possible and not supported.

Just wanted to clear that up so the OP isn't mislead.

[HenGus]

Surely, it is 3 single zones with an Evohome connected to the three motorised valves. Why cannot the built in sensor in the Evohome controller be used to open a motorised valve which, in turn, informs the boiler that heat is required. Surely, it is doing the same as Nest in this configuration?

Put it another way, if I had one heating zone and no TRVs, why can't Evohome be used as a simple thermostat/timer? I have 3 HR92s in my hall/landing controlled by the Evohome sensor. I am pretty sure that if I replaced the HR92s with manual TRVs, the heating would still come on in this zone. However, the zone would also come on when other zones demanded heat.

[JohnDoe]

The BDR91 works in the 868MHz wifi band. It talks to the controller (in my situation) and the Controller is wired to the boiler. If you wanted to site the 3 BDRs next to the boiler then, in theory, they should have the same range as the HR92s.

The Evohome Shop does offer a wifi test kit.

https://theevohomeshop.co.uk/en/hone...-test-kit.html

Maybe I'm getting confused with the terminilogy but I thought the controller is the screen which wirelessly communicates with the 'other stuff' i.e. hot water BDR91 and heating BD91. If the latter are to be in the cellar just 30 cm from the boiler, it will have a hard time communicating with them. Consequently, I wondered if the wiring of these (BDR91s) can be extended such that I have them perhaps somewhere near the ground floor (as opposed to the cellar).

[DBMandrake]

Surely, it is 3 single zones with an Evohome connected to the three motorised valves. Why cannot the built in sensor in the Evohome controller be used to open a motorised valve which, in turn, informs the boiler that heat is required. Surely, it is doing the same as Nest in this configuration?

But that's not what was being talked about - you were implying that you could simply leave out the HR92 for the zone the controller was sensor for and have the controller as a sensor with no zone actuator of any type, and still fire the boiler - which you can't. Except in the special single zone mode, you always have to have at least one actuator that is specific for each zone.

A BDR91 and zone valve CAN be the actuator for the zone (as I mentioned) provided that the zone valve only controls the room being monitored by the sensor - it's no good trying to use a zone valve for an entire floor unless you don't want any individual control of rooms.

Put it another way, if I had one heating zone and no TRVs, why can't Evohome be used as a simple thermostat/timer?

One heating zone is a special case - you can do that with no actuators except a boiler relay. However as soon as you have two or more zones you can't do this.

I have 3 HR92s in my hall/landing controlled by the Evohome sensor. I am pretty sure that if I replaced the HR92s with manual TRVs, the heating would still come on in this zone. However, the zone would also come on when other zones demanded heat.

No you can't do that, because you must have at least one actuator for the zone - a temperature sensor is not enough.

I don't know about earlier models but the Wi-Fi model won't even let you create a zone without an actuator in it if you try. And if you try to unbind existing HR92's from an already configured zone, leaving none in the zone you'll get comms errors after a few hours when the controller wonders what happened to the missing HR92(s).

[JohnDoe]

Think the topic veering away from my queries. Please could I please request some help with my posts?

[DBMandrake]

Maybe I'm getting confused with the terminilogy but I thought the controller is the screen which wirelessly communicates with the 'other stuff' i.e. hot water BDR91 and heating BD91. If the latter are to be in the cellar just 30 cm from the boiler, it will have a hard time communicating with them. Consequently, I wondered if the wiring of these (BDR91s) can be extended such that I have them perhaps somewhere near the ground floor (as opposed to the cellar).

You're right - the controller has the touch screen user interface and communicates to all other devices including BDR91 wirelessly - I think HenGus just mis-spoke. All it needs is a permanent supply of power.

Depending on your system you only need three or four wires to a BDR91 so if necessary you could bring a cable up from the cellar into the floor above and mount the BDR91's there - although you may not find that necessary depending on the results of a signal test.

BTW the 30cm recommendation is to keep multiple BDR91's at least 30cm from each other, and also 30cm from large metal objects like a boiler.

[JohnDoe]

You're right - the controller has the touch screen user interface and communicates to all other devices including BDR91 wirelessly - I think HenGus just mis-spoke. All it needs is a permanent supply of power.

Depending on your system you only need three or four wires to a BDR91 so if necessary you could bring a cable up from the cellar into the floor above and mount the BDR91's there - although you may not find that necessary depending on the results of a signal test.

BTW the 30cm recommendation is to keep multiple BDR91's at least 30cm from each other, and also 30cm from large metal objects like a boiler.

Thanks!

So if I am to have a HR92 on every single radiator, I will need 1 x HW zone valve, 1 x heating zone valve, 2 x BDR92s, 1 x hot water kit, 1 x controller?

Should I just remove the other 2 zone valves?

[HenGus]

But that's not what was being talked about - you were implying that you could simply leave out the HR92 for the zone the controller was sensor for and have the controller as a sensor with no zone actuator of any type, and still fire the boiler - which you can't. Except in the special single zone mode, you always have to have at least one actuator that is specific for each zone.

A BDR91 and zone valve CAN be the actuator for the zone (as I mentioned) provided that the zone valve only controls the room being monitored by the sensor - it's no good trying to use a zone valve for an entire floor unless you don't want any individual control of rooms.

One heating zone is a special case - you can do that with no actuators except a boiler relay. However as soon as you have two or more zones you can't do this.

No you can't do that, because you must have at least one actuator for the zone - a temperature sensor is not enough.

I don't know about earlier models but the Wi-Fi model won't even let you create a zone without an actuator in it if you try. And if you try to unbind existing HR92's from an already configured zone, leaving none in the zone you'll get comms errors after a few hours when the controller wonders what happened to the missing HR92(s).

Let's put this in its simplest form. A house with an 'S' plan and manual TRVs. I believe that an Evohome controller can be used instead of a hall thermostat and timer - without any HR92s. It would be a single zone.

If the OP has three valves, then I also believe that he could use 3 Evohome controllers - one on each floor connected to its zone valve in the way he suggested he could with Nest.

With 3 Evohome controllers, he could leave two floors without HR92s and he could have one floor with HR92s.

It is not how Evohome is designed to work but I believe that it would work.

[JohnDoe]

Been on the phone to the Evo Home Shop who have suggested that if I am to provide every radiator with a HR92, I'd only need 1 motorised zone valve for hot water (none for heating to allow the HR92s to have fine control), 1 hot water kit, 1 BDR91, 1 or 2 control panels (as required).

[dty]

That's basically what I have too. 12 HR92s right now (25 in total before long, rads that don't have HR92s have mechanical TRVs right now), no CH valve (not possible with my pipework), DHW kit with BDR91 for HW valve, BDR91 to fire boiler.

[JohnDoe]

That's basically what I have too. 12 HR92s right now (25 in total before long, rads that don't have HR92s have mechanical TRVs right now), no CH valve (not possible with my pipework), DHW kit with BDR91 for HW valve, BDR91 to fire boiler.

Mine is set-up with all the necessary traditional zoning but not required according to Evo Home SHop.

Once you add the rest of the radiators, will you need more than 12 zones? If so, will you then get 2 control panels?