Hive with Vaillant boilers?

[gerbils]

We are getting a Vaillant ecoFIT Pure 418 next week and hope that it will work with our existing Hive system. From their litterature the boiler will give a max 19kw of heating output and 25kw for domestic hot water. This confuses me as it's a heat-only boiler but if true it's perfect for us as our cylinder has a max input of 24kw thus boosting our recovery time by 7 mins.

However I am unsure how this works, I assume when you call for hot water it kicks in at a higher power; but will this work with Hive I wonder or will I need Vaillant's own smart hub?

Vaillant were my first port of call and after speaking to 3 people, all of whom had no idea, I gave up.

 

[Mottie]

We have Hive with our 418 EcoTEC plus. Unless you are using the dedicated Vaillant controls, you cannot have different heating and hot water temperatures.

 

[gerbils]

Darn! So I assume when heating the hot water cylinder, it would do so at 18kw rather than their advertised 25kw?

If this is true I am unclear how it would modulate as we'd not want that on water, we want it to heat up as quickly as possible - especially when 4 people all want a bath from our 160L cylinder!

 

[Mottie]

Darn! So I assume when heating the hot water cylinder, it would do so at 18kw rather than their advertised 25kw?

‘Fraid so. Our 150 litre HWC (Unvented) does heat up pretty quick though and I only have my boiler max output set at 15Kw and the flow temperature at 62°. Mind you, we rarely have baths, just showers. Perhaps a more efficient and/or a larger HWC might help?

 

[gerbils]

The cylinder is brand new so hopefully fairly efficient. 1.7kw per 24 heat loss if that means anything. 160L

I will see how we go, and if desired we can always buy the Vaillant controls.

I assume the setting on the boiler itself for heating temperature and hot water temperature is the same and it will ignore the hot water one?

I think the default is 75 for both. I will follow your lead on 62

 

[Mottie]

I assume the setting on the boiler itself for heating temperature and hot water temperature is the same and it will ignore the hot water one?

Yeah, I don’t even think the hot water setting can be changed without the Vaillant controls although mine is the Plus so might be different to the pure.

 

[gerbils]

Yeah, I don’t even think the hot water setting can be changed without the Vaillant controls although mine is the Plus so might be different to the pure.

I don't have the boiler yet, but looking at the manuals it suggests you can seperate HW and CH temperatures. Frustratingly it makes no mention of needing their thermostat.

I'll report back next week.

 

[Mottie]

Frustratingly it makes no mention of needing their thermostat.

I’m not sure about the thermostat, but it’s their controller that’s needed. It mentions that in the very top left hand of the page you attached. That will surely interfere with the Hive controller. Also, the Hive (and most non-Vaillant controls) work on 240v. The Vaillant controllers work on 24v. It’s quite common for Vaillant installers to forget to remove the 24v link in the boiler when you are using non-Vaillant controls giving you all sorts of problems from day 1!

 

[gerbils]

I’m not sure about the thermostat, but it’s their controller that’s needed. It mentions that in the very top left hand of the page you attached. That will surely interfere with the Hive controller. Also, the Hive (and most non-Vaillant controls) work on 240v. The Vaillant controllers work on 24v. It’s quite common for Vaillant installers to forget to remove the 24v link in the boiler when you are using non-Vaillant controls giving you all sorts of problems from day 1!

Thanks for the tip!

 

[gerbils]

It still says condition: controller not connected and seems to allow separate water temp...hmmm. Confusing.

 

[Mottie]

It still says condition: controller not connected and seems to allow separate water temp...hmmm. Confusing.

Maybe the Pure is different? What happens when both the heating and hot water are calling for heat - you only have one outlet on the boiler so it will only give out one temperature? Maybe with the Vaillant controllers it gives hot water a priority and shuts off the heating? My one supplies both heating and hot water at the same time when both are calling for heat.

 

[gerbils]

Maybe with the Vaillant controllers it gives hot water a priority and shuts off the heating? My one supplies both heating and hot water at the same time when both are calling for heat.

I am assuming that is the case. I have called them and spoke to 3 people but they literally have no idea; one is convinced I am talking about a combi as "the water & heat output would be the same" despite both website spec sheet on installer website and manual suggesting otherwise.
Off to a bad start with customer services and it's not even been fitted yet -

 

[Mottie]

I am assuming that is the case. I have called them and spoke to 3 people but they literally have no idea; one is convinced I am talking about a combi as "the water & heat output would be the same" despite both website spec sheet on installer website and manual suggesting otherwise.
Off to a bad start with customer services and it's not even been fitted yet -

I just can’t see how an 18Kw boiler can put out 25Kw of heat! The other way round, no problem. As far as I know, it’s the water TEMPERATURE that is different on the boiler with Vaillant controls - you may want a low temperature for the heating efficiency and condensing but higher temperatures for hot water to combat legionella. I think @Harry Bloomfield might know as he has a Vaillant boiler with the Vaillant controls and is a lot more knowledgeable about it. I’ve mentioned him so he may be able to chip in.

 

[gerbils]

Here's the spec sheet which mentions it.

 

[gerbils]

Update from Vaillant on this:

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Good Morning,

Thank you for your email.

The boiler will only be able to tell the difference between heating and hot water when installed with our controls.

Kind Regards
Technical Advisor

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