Viessmann 200-W Gas Boiler - The most efficient boiler sold in the UK?

Alnat1

@Screwdriva As you're close to sea level and also live next to a large volume of water, this will mean generally higher humidity levels surrounding your property than many of us have.

Does this affect your indoor levels and is it something you monitor? Could this be affecting how much gas you have to use to heat your property?

JSHarris

Alnat1 said:

@Screwdriva As you're close to sea level and also live next to a large volume of water, this will mean generally higher humidity levels surrounding your property than many of us have.

Does this affect your indoor levels and is it something you monitor? Could this be affecting how much gas you have to use to heat your property?

We live inland, but the outside humidity here has been floating between 92% and 100% for days now.  Just a consequence of the mild, wet, weather, lack of wind and living at the bottom of a steep valley I think.  Does make a big difference to the heating requirement.  Been so mild here we've not had the heating come on for the past two days and it was still over 22°C in the living room yesterday evening.

Screwdriva

Reed_Richards said:

I would have thought that you would have made sure any boiler you bought had it

The old Worcester boiler came with the house when we purchased it. That said, it took lots of research and learning about weather compensation, modulation and heating efficiency before I discovered the Viessmann 200 and an installer (Urban Plumbers) who knew how to get the most out of it.

Alnat1 said:

@Screwdriva As you're close to sea level and also live next to a large volume of water, this will mean generally higher humidity levels surrounding your property than many of us have.

Does this affect your indoor levels and is it something you monitor? Could this be affecting how much gas you have to use to heat your property?

Marginally perhaps, but I have no way to confirm this. We do have a hygrometer to monitor humidity and rarely ever exceed 90%. We often hover around 60% even in the colder months. 

Following this thread and the very useful comments/ questions shared, I visited my neighbour's property (other side of the semi-detached) and asked if they'd be willing to share their heating bills.

Upon review, and to my surprise, despite having underfloor heating on all 3 floors (we only have it one one) and an oversized 10 year old Worcester Bosch 30 kW System boiler, their gas consumption was between 17-28% higher than our household, depending on the month.

The property layout is identical but we do receive more sunlight as we are South facing. Not scientific but does give the a new boiler a bit more credit. Incidentally, the neighbors have asked me to arrange in introduction to a known Viessmann installer

MeteredOut

Screwdriva said:

The property layout is identical but we do receive more sunlight as we are South facing. Not scientific but does give the a new boiler a bit more credit. Incidentally, the neighbors have asked me to arrange in introduction to a known Viessmann installer

I know you're very keen to give the Viessmann kudos - and some may consider going out of your way to ask your neighbours for there energy bills, and then spending time analysing them, is pretty extreme - but thinking this is any way confirms or verifies your 31% less consumption claim is stretching things somewhat!

Did you quiz them on their usage patterns, boiler timings, thermostat and TRV settings, cooking habits, shower habits, working from home v working in office % etc etc.

There are so many variables outside of house size, layout and aspect. I'm not sure you mentioned before you were semi-detached. Perhaps your neighbours increased their heating about the same time you got your new boiler and you benefited from the heat through the shared wall.

Get them to do a like-for-like swap with the Viessmann, changing *nothing* else, then come back please

JSHarris

Logically a 30% improvement cannot be down solely to a change in boiler efficiency, unless the old boiler was extremely old or the old system was set up very badly.  Condensing boilers rarely drop below 80% efficiency and rarely exceed 99% efficiency, so the greatest possible margin would be around 19%, and this is right at the extremes of possible boiler performance.

More likely that other things done at the same time have contributed significantly to the observed improvement, with the boiler change just being a part of that (might not even be the major part of the improvement).

Screwdriva

MeteredOut said:

I know you're very keen to give the Viessmann kudos - and some may consider going out of your way to ask your neighbours for there energy bills, and then spending time analysing them, is pretty extreme - but thinking this is any way confirms or verifies your 31% less consumption claim is stretching things somewhat!

Did you quiz them on their usage patterns, boiler timings, thermostat and TRV settings, cooking habits, shower habits etc?

Get them to do a like-for-like swap with the Viessmann, changing *nothing* else, then come back please

Incidentally, that's the plan. Swap out the old boiler for a V200 and do nothing else.

Will gladly come back their usage data for the benefit of all, but it must be shared that I care more for the scraps I scrape off my breakfast plate than whether you or anyone else views what I have shared as extreme. 

MeteredOut

Screwdriva said:

MeteredOut said:

I know you're very keen to give the Viessmann kudos - and some may consider going out of your way to ask your neighbours for there energy bills, and then spending time analysing them, is pretty extreme - but thinking this is any way confirms or verifies your 31% less consumption claim is stretching things somewhat!

Did you quiz them on their usage patterns, boiler timings, thermostat and TRV settings, cooking habits, shower habits etc?

Get them to do a like-for-like swap with the Viessmann, changing *nothing* else, then come back please

Incidentally, that's the plan. Swap out the old boiler for a V200 and do nothing else.

Will gladly come back their usage data for the benefit of all, but it must be shared that I care more for the scraps I scrape off my breakfast plate than whether you or anyone else views what I have shared as extreme. 

It wasn't your view I stated could be extreme, but asking neighbours for their energy bills so you could try get additional evidence to back up a claim you made on the internet.

I like the food analogy though. I assume you end up scraping food off your breakfast plate after you grossly overestimated how hungry you were?

Screwdriva

MeteredOut said:

I like the food analogy though. I assume you end up scraping food off your breakfast plate as you grossly overestimated how hungry you were?

More that there were things on the plate simply not worth digesting. 

MeteredOut

Screwdriva said:

MeteredOut said:

I like the food analogy though. I assume you end up scraping food off your breakfast plate as you grossly overestimated how hungry you were?

More that there were things on the plate simply not worth digesting. 

Reminds me of my daughter when younger - she refused to eat some foods before even tasting them, adamant she did not like them.

How long can we keep this analogy going

Seriously though, I'd be keen to hear the results from a like-for-like replacement by the neighbour, if they plan to do so.

Reed_Richards

Screwdriva said:

Following this thread and the very useful comments/ questions shared, I visited my neighbour's property (other side of the semi-detached) and asked if they'd be willing to share their heating bills.

Upon review, and to my surprise, despite having underfloor heating on all 3 floors (we only have it one one) and an oversized 10 year old Worcester Bosch 30 kW System boiler, their gas consumption was between 17-28% higher than our household, depending on the month.

The property layout is identical but we do receive more sunlight as we are South facing. Not scientific but does give the a new boiler a bit more credit. Incidentally, the neighbors have asked me to arrange in introduction to a known Viessmann installer

Just to be absolutely 100% crystal clear, you mean their gas consumption was 17-28% higher than your household used to be before you got the new boiler and made the other changes?