Please help choose: WB Greenstar 4000 or Vaillant ecoTec Plus 832 combis.

MysteryMe

I don't know if this is in anyway a competitive price (esp as install is by BG) but I see Costco have started selling the same WB boiler mentioned in this thread for £2599.99 installed
https://www.costco.co.uk/Appliances/Cooling-Air-Treatment-Heating/Heaters-Boilers/c/cos_8.4.4?q=:price-desc:brand:Worcester+Bosch&utm_campaign=FY25P3W4c&utm_medium=email&utm_source=email&utm_content=Half-3&utm_term=bosch&sc_src=email_18121&sc_lid=4419242&sc_uid=LRrvZSSVNV&sc_llid=702228

ThisIsWeird

MysteryMe said:

I don't know if this is in anyway a competitive price (esp as install is by BG) but I see Costco have started selling the same WB boiler mentioned in this thread for £2599.99 installed
https://www.costco.co.uk/Appliances/Cooling-Air-Treatment-Heating/Heaters-Boilers/c/cos_8.4.4?q=:price-desc:brand:Worcester+Bosch&utm_campaign=FY25P3W4c&utm_medium=email&utm_source=email&utm_content=Half-3&utm_term=bosch&sc_src=email_18121&sc_lid=4419242&sc_uid=LRrvZSSVNV&sc_llid=702228

Also interesting, it includes a Hive. That won't get the best out of it.

Am I fixating too much? Will a 'correct-protocol' control system make that much difference? Enough to justify the purchase price?

Who the hell knows.

FreeBear, where are you

FreeBear

ThisIsWeird said:

MysteryMe said:

I don't know if this is in anyway a competitive price (esp as install is by BG) but I see Costco have started selling the same WB boiler mentioned in this thread for £2599.99 installed
https://www.costco.co.uk/Appliances/Cooling-Air-Treatment-Heating/Heaters-Boilers/c/cos_8.4.4?q=:price-desc:brand:Worcester+Bosch&utm_campaign=FY25P3W4c&utm_medium=email&utm_source=email&utm_content=Half-3&utm_term=bosch&sc_src=email_18121&sc_lid=4419242&sc_uid=LRrvZSSVNV&sc_llid=702228

Also interesting, it includes a Hive. That won't get the best out of it.

Am I fixating too much? Will a 'correct-protocol' control system make that much difference? Enough to justify the purchase price?

Who the hell knows.

FreeBear, where are you

I'm busy.

Currently tweaking some code for OpenTherm now that is has been accepted in to ESPHome.

In my (somewhat biased) opinion, having a smart(er) control system that can control modulation helps to drive up efficiency. With a system or heat only boiler, it makes a huge difference if you want priority DHW as it allows you to up the flow temperature when heating the tank, and running lower for the heating system. But to heat effectively with low flow temperatures, you do need properly sized radiators suitably balanced and with an appropriate pump speed.

Having a thermostat that can "do" modulation helps to reduce short cycling - On start up, boilers burn quite a bit of gas for a short period, wreaking efficiency. It also increases wear & tear on internal components which could affect long term reliability.

So regardless of which boiler you go for, it is well worth spending a bit more to get a (programmable) thermostat that talks the same language as the boiler. Just get one that doesn't depend on the cloud for the smarts.

ThisIsWeird

FreeBear said:

ThisIsWeird said:

MysteryMe said:

I don't know if this is in anyway a competitive price (esp as install is by BG) but I see Costco have started selling the same WB boiler mentioned in this thread for £2599.99 installed
https://www.costco.co.uk/Appliances/Cooling-Air-Treatment-Heating/Heaters-Boilers/c/cos_8.4.4?q=:price-desc:brand:Worcester+Bosch&utm_campaign=FY25P3W4c&utm_medium=email&utm_source=email&utm_content=Half-3&utm_term=bosch&sc_src=email_18121&sc_lid=4419242&sc_uid=LRrvZSSVNV&sc_llid=702228

Also interesting, it includes a Hive. That won't get the best out of it.

Am I fixating too much? Will a 'correct-protocol' control system make that much difference? Enough to justify the purchase price?

Who the hell knows.

FreeBear, where are you

I'm busy.

Currently tweaking some code for OpenTherm now that is has been accepted in to ESPHome.

In my (somewhat biased) opinion, having a smart(er) control system that can control modulation helps to drive up efficiency. With a system or heat only boiler, it makes a huge difference if you want priority DHW as it allows you to up the flow temperature when heating the tank, and running lower for the heating system. But to heat effectively with low flow temperatures, you do need properly sized radiators suitably balanced and with an appropriate pump speed.

Having a thermostat that can "do" modulation helps to reduce short cycling - On start up, boilers burn quite a bit of gas for a short period, wreaking efficiency. It also increases wear & tear on internal components which could affect long term reliability.

So regardless of which boiler you go for, it is well worth spending a bit more to get a (programmable) thermostat that talks the same language as the boiler. Just get one that doesn't depend on the cloud for the smarts.

Thanks FreeBear, and I agree that it 'must' make a reasonably measurable difference.
Which brings me full cycle - which combi boiler, and which off-the-shelf controller? 

FreeBear

ThisIsWeird said: Which brings me full cycle - which combi boiler, and which off-the-shelf controller?

Viessmann 050 or 100 with a Wiser single channel thermostat.

ThisIsWeird

Thank you. I'll pass that on (they'll be reading this too).

ThisIsWeird

Veissman got back to me; "The Vitodens 050-W does not have any support for Smart TRV's, so as this is part of the requirement we suggest you go third party. Opentherm is an option for connectivity on the Vitodens 050-W, So controls from Drayton, Tado, Nest and EPH to name a few are several makes that our Installers have used previously."

No mention of 'Wiser', but that's not to say it ain't as good. Why do you prefer it, FreeBear?

And Veissman boilers are every bit as good as WB and Vaillant?

Cheers.

FreeBear

Wiser is made by Drayton (part of the Schneider Electric group).

My preference for Viessmann over Vaillant & WB is the fact that it supports OpenTherm. They also offer 10 year warranties, so that is another plus over some of the others. I've not had need to invoke the warranty, so can't comment on their response to claims.

One thing I would say though - The quality of installation and the ability of the GS engineer to set the boiler up correctly will have a huge impact. I'm finding that my boiler was bunged in with no changes to the default settings which affects performance. Some of the settings (flow & DHW temperatures) are easily changed via the front panel or my "thermostat". Others like OpenTherm conectivity and pump speed needs to be done through the service menu. Lots of button pushes and careful reading of the installation manual required.