Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
10kW Viessmann Vitocal 200-A with Vitocal 222-A
Good Morning All
After following the threads on this site, I feel I need to introduce myself and provide a summary of my system.
We moved into a new barn conversion in 2022, the majority of the work was completed by myself and my wife, employing trades as required. The build was effectively a new skin inside the old barn, all on one floor, of 195sq meters, underfloor heating throughout. Because of this we knew exactly how much insulation was in the property and the U values of all the windows and doors. Theoretically this should of given us an accurate energy performance figure to size the air source heat pump. We have a 10Kw Viessmann Vitocal 200-A external unit, with a Vitocal 222-A Indoor Unit with integrated 220L DHW cylinder. As we installed all the insulation and took great care in making it to the best we could, and to a higher standard than most builders, the pump is slightly oversized for the property, this doesn’t seem to be a problem with the Viessmann unit, and it modulates its output down to about 25% capacity very easily. Coupling the heat pump with the underfloor heating, and a low loss property, means we can run it at low temperatures, current WC slope has 27° @ +10, 30° @ 0 and 32° at -10.
We used our Local plumber to do the install, he was keen to start fitting heat pumps even though this was his first, we were very happy with his work using his plumbing experience has avoided some of the problems others have had. Because he hadn’t fitted any before I agreed to set up all the WC etc. and feed back to him my findings. At some point in the future I will post my experiences with this.
Welcome to the forums @mikef – how is your system holding up? You please with it so far?
🔥 Britain’s Heat Pump Shitshow
How Installing a Heating System Became a National Nervous Breakdown
Pre-order with free UK shipping.
Rewritten and updated for 2027
📘 From Zero to Heat Pump Hero
🛠️ Bodge Buster
New to heat pumps?
Take the Heat Pump Fundamentals course and use INTRO50 at checkout for 50% off.
- 27 Forums
- 2,750 Topics
- 64.7 K Posts
- 1,024 Online
- 7,158 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
RE: Who's your electricity provider and what's your tariff?
@papahuhu I prefer to look at it simplistically. We d...
By Old_Scientist , 3 hours ago
-
RE: To re-pipe or not to re-pipe? Moving from oil boiler to air source heat pump.
Sooooo, what did we do in the end? We approached three ...
By Penval , 3 hours ago
-
RE: How Accurate Is My DIY Heat Loss Calculation?
D'oh - of course. I shouldn't post before my brain is f...
By Old_Scientist , 8 hours ago
-
RE: Questions about A2A for heating as well as cooling
@rob-of-york I would concur with the underfloor insulat...
By Toodles , 10 hours ago
-
RE: New Vaillant Arotherm controls link to existing thermostats ; wired vs wireless
Nothing attached! I have rads but UFH makes the case ...
By JamesPa , 10 hours ago
-
RE: Cooling with air to water heat pumps
Passive cooling should always be the first call. Keep ...
By JamesPa , 11 hours ago
-
RE: Do I add Air Con or MVHR to existing A2W ASHP?
@rob-of-york Thank you, I’m thinking along these same l...
By Toodles , 1 day ago
-
@Mars Good questions! The downstairs unit did the maj...
By Rob of York , 1 day ago
-
RE: Volumisers in Heat Pump Systems: Does Placement Matter?
@dave, I think @jamespa has probably identified the mos...
By Mars , 2 days ago
-
RE: Plug and play solar. Thoughts?
My thought is simple. Bring it on and bring on plug in...
By JamesPa , 2 days ago
-
RE: Heat Geek mini store vs pump size
Yes I agree, that’s why Heat Geek have most likely sele...
By Tomtheheatingengineer , 3 days ago
-
@tomtheheatingengineer, thank you, and welcome to the f...
By Mars , 3 days ago
-
RE: HeatGeek vs Octopus surveys: puzzling disparity - any ideas why?
@majordennisbloodnok @tomtheheatingengineer For my ...
By JamesPa , 3 days ago
-
RE: Is the "divide by 2900" rule still valid?
Really flow rate is a pipework limitation not a water p...
By JamesPa , 4 days ago




