WB Greenstar boiler technical info required

[Exedon]

My other conundrum is....why is a Honeywell NO zone valve 3 times more expensive than a Honeywell NC zone valve!

It's not you need to shop around! We pay around £90
Some currently on ebay for £70

 

[Mister Banks]

It's not you need to shop around! We pay around £90
Some currently on ebay for £70

The valve description on eBay advert says it’s a normally open but the pic on the box shows a normally closed. Is that normally how they are packaged?

 

[Mister Banks]

I have been in touch with WB tech support who tell me that my boiler can’t do different flow temps even with the Easycontrol so that’s a non starter. I won’t gain anything by swapping Wiser to Easycontrol.

I could still have a PDHW configuration but would it be worth doing given that the boiler has a set flow temp for CH and HW?

 

[MNW67]

I could still have a PDHW configuration but would it be worth doing given that the boiler has a set flow temp for CH and HW?

Surely that would be self-defeating? You would be giving up the flexibility of having heating and hot water on at the same time, and getting no benefit in return.

 

[Mister Banks]

Surely that would be self-defeating? You would be giving up the flexibility of having heating and hot water on at the same time, and getting no benefit in return.

I can see a few benefits......

1. Changing the NC CH zone valve to a NO zone valve will save a tiny bit of electricity
2. Having the CH on when the DHW is off will help the boiler stay in condensing mode for longer hence saving a bit of gas
3. It will fix my issue where sometimes when the CH zone valve closes the pipework knocks
4. No need for the auto bypass valve

 

[Rxt_ian]

I’m not sure how committed to the idea you are, but I recently got my 2019 Greenstar 15 Ri to do hot water priority with different flow temps.

It took building and configuring an EMS to wifi bridge you can buy from https://bbqkees-electronics.nl/

Its controlled via home assistant to pick up the call for heat from the HW tank thermostat via a mains coil relay and change the flow temp and max burner power via EMS.

I didn’t see this capability documented anywhere, I’m guessing since it’s a “bottom of the range” boiler WB want you to buy a fancier one to get this functionality that’s actually already there….
I only tried as the previous owners had a British Gas telemetry module hooked up to the EMS bus which I modded to a cheap ESP32 I had from another project anyway, so my initial investment was zero.

 

[Mister Banks]

I thought it strange that the Bosch Easycontrol connects directly to the EMS bus yet it is still only an on/off control and according to WB tech support can not change the flow temp.

 

[MNW67]

I didn’t see this capability documented anywhere, I’m guessing since it’s a “bottom of the range” boiler WB want you to buy a fancier one to get this functionality that’s actually already there….

Trying to get information from WB about this is like getting blood from a stone. All they will tell you is that the only way to make it work is by using their integral diverter valve kit.

On the website you linked to it seems to say that your boiler isn't compatible? But clearly you've made it work!

 

[Mister Banks]

Trying to get information from WB about this is like getting blood from a stone. All they will tell you is that the only way to make it work is by using their integral diverter valve kit.

On the website you linked to it seems to say that your boiler isn't compatible? But clearly you've made it work!

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If WB tech support are to be believed the only way of doing PDHW on my 24i is to add the internal diverter kit but my boiler doesnt support multiple flow temps (according to tech support). I dont see the point of having an EMS bus and controls that don't do more than on/off control.

 

[MNW67]

If WB tech support are to be believed the only way of doing PDHW on my 24i is to add the internal diverter kit but my boiler doesnt support multiple flow temps (according to tech support).

Even with the integral diverter valve kit? The manual implies otherwise

I dont see the point of having an EMS bus and controls that don't do more than on/off control.

According to the link from @Rxt_ian the Easy Control has very limited EMS functionality. But there are other WB controls which also use EMS and may possibly do more.