Air Source Heat Pump Install pt.2 - Viessmann Vitocal

[@no-ic3rg]

Cracking job. Very high standard of work

[@loving-plumbing]

Thank you

[@Foss1985]

We’re installing one next month, 8kW unit (same turn down as a 6kW - so went for this to improve the DHW recovery). I’m thinking of using a grid switch with 3 x 20A DP switches and fuse modules. We’re going all open loop with weather comp, 16mm UFH in screen downstairs and 12mm UFH (grooved chipboard) upstairs…. Looking forward to it

[@loving-plumbing]

Sounds awesome mate. Let me know how you get on. 👍

[@johnboddington]

Great job and install again. I'm sure it will perform well. Shame installs like this are totally unaffordable for the vast majority.😢

[@loving-plumbing]

@@johnboddington Agree. Thanks for watching

[@dominichalliday8929]

Cracking job 👏

[@loving-plumbing]

Thank you

[@mohammadahmad0790]

Are the 3x spurs actually three separate cables going back to 3x 16amp breakers on the fuseboard? Would the viessman be able to identify if it was one breaker split into 3 spurs?

[@loving-plumbing]

Definitely needs to be 3x 16AMP breakers on the board. They did check ✅. Annoyingly I know. Apparently they might be accepting just one wired in soon as this is obviously hard to achieve if retro fitting.

[@griffithsheating]

@@loving-plumbingthe units used to throw a fault of only one leg was connected I think there was a software update to allow one leg without the fault. I’ve fitted them with only one leg connected as it’s a stupid setup having 3 RCDs and spurs.

[@UrbanPlumbers]

@@loving-plumbing@loving-plumbing, you don't have to wire all 9kW!!! No need for that. You can only wire a single phase to the backup heater.

[@loving-plumbing]

@@UrbanPlumbers Not according to Viessmann. Although they are apparently changing that requirement.

[@normanboyes4983]

Very nice job. Interested in the Viessmann design side of things because this is crucial to success, who did the actual heat loss calculation - did Viessmann do that themselves? I ask because it is such an integral part of the design process and all the downstream MWT and emitter sizing results from it. On the bracketing of the external primaries - yes, external pipe support (around the primary pro) does not look as good but Munsons are effectively conductive bridges to the brick wall so not as thermally efficient. Finally, is the homeowner up to speed with fine tuning the weather compensation (curve and level)going forward or are you intending to tweak this remotely for them? Thank you for sharing, it would be good to get an update post 24/25 winter, in terms of system performance and customer satisfaction.👍

[@loving-plumbing]

@@normanboyes4983 so this property did have a heat loss carried out by myself, Viessmann as well as full SAP calculations. Viessmann actually provides some really good emitter sizing software as part of the umbrella scheme. It's more difficult with the underfloor. Especially with different floor finishes. Only time will tell. I'm looking forward to the winter ❄️. My main concern is that it's too hot 🥵

[@normanboyes4983]

@@loving-plumbing I understand your concern but - keep the faith. It’s all about design and you and Viessmann have done the necessary. I strongly suspect it will perform absolutely fine once the curve is dialled in, getting the curve as ‘lean’ as possible is key. My experience based as a user of a gas V200 in an existing build. I changed quite a few rads to better match heat loss at reduced DT. It’s an all rad system, all TRV heads are off and in a box and I have no internal reference - pure weather comp. I deployed half a dozen bluetooth thermometers around the house while I was dialling in the curve - I have no overheating anywhere in the house we have never been so comfortable (40°C flow at -2).

[@loving-plumbing]

@@normanboyes4983 that's awesome news. That's how I initially got the curve set. I deployed some thermostats also. I definitely dialed it down, which I guess is a good thing. Will do the same thing in the winter. They have the luxury of MVHR to also help the equilibrium. That's for the comments. I will try my best to post updates. Thanks for watching and thanks for the advice.

[@handle1196]

When you say Viessmann have some good emitter sizing software, how did its results or compare to you doing the calculations yourself and using a conversation factor based on your heat loss inputs? Thanks for creating the video and breaking it down. ​@loving-plumbing

[@brotherjohnno]

Apologies in advance for what is probably a dumb question, but with the open loop system, can i assume your rads upstairs are 'on' whenever the UFH is on?

[@loving-plumbing]

That is correct. The system is always on covering any heat loss that may be happening. Keeping flow temps low.

[@JustInterested-xt3ud]

Interested to see how they get on with open loop control and no control on the upstairs rads, they may end up with a window open at night :-)

[@loving-plumbing]

Definitely a concern I had but so far seems ok. They have a set back temperature of 18c which kicks in early eve just to try and make things more comfortable

[@danielwatson8778]

The sensor, use a white pvc conduit end box, screwed over the pocket and then 20mm flex conduit across to the wall….

[@temp3rd103]

Freeze valves need a minimum of 150mm below

[@loving-plumbing]

Where did you get that information from?

[@loving-plumbing]

I've found it cheers. It's just recommended but makes sense. Unfortunately they also need to be at the lowest point of the flow and return. Bit difficult the way Viessmann is piped up. Thanks 👍👍👍

[@alimack5489]

Cracking job, but these installs are so far removed from reality for normal people these unit are what 6/7k plus near enough 10k plus for the installation including underfloor etc. ticks a box yes, im sure the owners are more than happy when they pull off in a range rover having this at home.

[@loving-plumbing]

I definitely think as far as KW size is concerned they are absolutely fine. When an accurate heat loss survey is carried out on a property you would be surprised how little you actually need. But yes, the cost is definitely an issue. Thanks for watching 👍.

[@normanboyes4983]

What is a ‘normal people’?

[@alimack5489]

@@normanboyes4983 people who don’t have 15 thousand pounds to spend on a central heating system mate….