Viessmann Vitodens 200-W

[tonybhoy]

Chrishutt wrote

As for claims of 40% savings with weather compensation, that is complete cobblers

It isin't and its one point on this thread where I agree with Sanj.
Why don't you stick to what you know ?.
How many top end commercial compensator controllers have you fitted and set up in domestic premises ?.

Stewart Purchase from Viessman UK quotes savings of 15% when using a WC or as he puts it "a weather sensitive control" and condensing boiler in this month's gas installer,letters page 20.
But they only quote 2% seasonal efficiency .

 

[sanj.varah]

Sanj seems to be confused about pipe threads. DN 20mm is the same thread as ¾" BSP and R1 is the same as 1" BSP. Male threads are normally tapered (unless they are union or compression threads) and female threads are parallel.

Sorry I should have made myself clearer.

The jig that comes with the vitodens 300 WB3B (to be specific) comes with a jig that will only take pre threaded pipe, then make the seal on the threads. In the UK that is not common practice, its more common to wedge up a bit of 22mm and then do a compression joint with an olive. You need an iron-compression converter to take normal pipe with a viessmann.

3/4" BSP is british standard pipe thread, and then it gets complicated

G is pressure conection not made on the threads
R is pressure connection Made on the threads (male taper)
Rp is pressure connections made on the threads - parallel (IIRC)

Standard DIN spec is specify R type threads for water fittings. That isn't common practice in the UK. well i've seen a few cylinders and majority of them don't have the pressure connection on the threads.

I don't think 4% is that abnormal. However if you buy something like a vokera, stick weather compensation on it, i wouldn't expect much more than 10%. so i think a lot is to do with the controls and how you specify the system.

my 2pworth

 

[chrishutt]

Standard DIN spec is specify R type threads for water fittings. That isn't common practice in the UK. well i've seen a few cylinders and majority of them don't have the pressure connection on the threads.

Yes it is standard practice in the UK. Male threads are R (tapered) and Female threads are Rp (parallel), both being threads suitable for sealing on the threads. For practical purposes Rp is the same as a female G thread (where the thread is intended for compression purposes only) since the dimensions are identical.

Just to complete the picture, a taper female thread would be known as Rc, but these are rarely specified in Europe. You should be aware that Europe now has a common standard for these things, namely EN 10226 which is also ISO 7. The common standard for pipe threads that aren't intended to seal on the threads is ISO 228.

 

[Agile]

I don't think 40% is that abnormal.

my 2pworth

Perhaps not Sanjj but none of us believe what you have said about your winter heating bill being only £45.

You have not commented on that figure even though so many have questioned it so presumably you are intentionally adding to the confusion?

There was an on station instructor at one of the BBC transmitting stations during the 1970s who earned himself the nickname "Duff Gen Pete" !

Tony

 

[JohnD]

I had guessed it meant £45 pcm

 

[simond]

Come on Sanj, I want to know about the £45 gas bill. Please elaborate.

And while you are at it, tell me how you can improve a condensing boiler efficiency by 40% by applying weather compensation.

There could be a knighthood in it for you

 

[sanj.varah]

mmm.. I appreciate in commerical plumbing that threaded pipe is used. But in domestic all i've seen is compression joints. The Viessmann boiler takes threaded pipe - which i don't think is a standard UK method?

to answer the other question.

well previous boiler was halstead blamoral 18kW i think. Not sure entirely as I managed to break it while removing it.

Upgraded to Vitodens 300 and changed all the rads in the process. I also installed at least 2 rads in every room with a floor area of more than 16 square meters. this allowed for even heating albeit less furniture.

So my total surface area of rads is now probably about 3-4 times what I had before, all rads are either double or triple convectors. This allows an extremely low flow temperature of approx 45C on normal days. On very cold days <3C its about 55-60C (this is controlled by the boiler).

I then went and fettled with the settings as much as i could to get a good balance between, efficiency, heat up time and boiler modulation. Viessmann Germany offer a service under their Blauwe Aengel scheme to offer you assistance with boiler setup parameters. I took the liberty of using this. Also there are tips on the Viessmann De website.

Heating bill from September through to December was £45. British Gas said that based on an estimate (using the previous owners gas bills) they would have expected me to use somewhere in the region of £120 (assuming the unit costs are the same).

There are a few things i cannot account for:
1. My heating is on from 6am to 10pm and through the day when i'm at work on reduced output (16C room temperature)
2. I don't know what hours the previous owners had the system on for
3. I live by myself so the cost for heating water would be less
4. I've got a bay area which was just tile with timber studding and then plasterboard. I've insulated this as it was leaking heat like no end.

Allowing for all those factors, i think a fettled gas bill on the Halstead boiler using my parameters would be around 80-90quid. Hence I reckon I saved about 40%

 

[JohnD]

...Heating bill from September through to December was £45. British Gas said that based on an estimate ...

I think you need to read the meter and start talking facts not guesswork

 

[Doctor Drivel]

Heating engineers shouldn't even be allowed to call themselves that unless they are chartered. The term engineer is protected around the world to varying degrees but the politicians in the UK have let the term be used by any tom dick and harry who can read and use a screwdriver.

I agree. A service man is called a service engineer here. Ludicrous. In Italy and engineer is called "Engineer", as you would call a doctor. Doctor is only an education level. A doctor of medicine. There are doctors of science. We call a medical doctor his education level. He is a medical practitioner.

 

[sanj.varah]

...Heating bill from September through to December was £45. British Gas said that based on an estimate ...

I think you need to read the meter and start talking facts not guesswork

my bill was not an estimate. that was meter reading. the previous owners bill was based on meter readings as well (my meter is outside). Furthermore if you bothered to read my first post i did state "I reckon"

 

[tonybhoy]

...Heating bill from September through to December was £45. British Gas said that based on an estimate ...

I think you need to read the meter and start talking facts not guesswork

my bill was not an estimate. that was meter reading. the previous owners bill was based on meter readings as well (my meter is outside). Furthermore if you bothered to read my first post i did state "I reckon"

Wereabouts are you?

£200 for gas for the year,yer having a laugh mate.

I worked for a guy who was obsessed with his gas bills but even he can't get them down below £240 a year and he hardly puts his heating on.

I'm talking Glasgow ,Vokera Compact 28 SE boiler and a Honeywell CM927 RF and TRVs on all rads.

 

[JohnD]

...Heating bill from September through to December was £45. British Gas said that based on an estimate ...

I think you need to read the meter and start talking facts not guesswork

my bill was not an estimate. that was meter reading. the previous owners bill was based on meter readings as well (my meter is outside). Furthermore if you bothered to read my first post i did state "I reckon"

you just said it was an estimate. now you say it was based on a meter reading (I hope you meant *TWO* meter readings). Which is it?

 

[Paz328]

Upgraded to Vitodens 300 and changed all the rads in the process. I also installed at least 2 rads in every room with a floor area of more than 16 square meters. this allowed for even heating albeit less furniture.

So my total surface area of rads is now probably about 3-4 times what I had before, all rads are either double or triple convectors. This allows an extremely low flow temperature of approx 45C on normal days. On very cold days <3C its about 55-60C (this is controlled by the boiler).

So to gain the benefits of weather compensation, I really need to have oversized rads in each room to enable lower flow temps thus keeping the boiler in condensing mode for longer? I have been decorating my house and have changed 3 of the rads (in 3 rooms), but this was before I even considered weather comp. I'm not sure if i have oversized rads now.

 

[simond]

This Sanj chap is not a heating installer. Furthermore he seems adept at confusing the truth. We have heard stories about gas usage which have gone from claims of £45 per annum to £45 for a few months once challenged..

We have had tales of DIN threads being needed when this is total fiction.

He has been recommending boilers that are no longer imported into the UK.

He has been making claims of 40% for adding weather compensation when now he is backtracking and saying that his 40% efficiency was the total net benefit of throwing out a Halstead Balmoral, FFS! Which is what we could have told him at the start.

As usual, some misguided fool agreed with his 40% claim, even though Viessmann were on file as only expecting a max of 15% efficiency gain with weather comp. And 2% sedbuk.

Now we have a DIYer apparently designing his system on the basis of what Sanj is writing. It is the blind leading the blind. Sometimes the internet is a misleading place full of fools.

 

[Doctor Drivel]

Upgraded to Vitodens 300 and changed all the rads in the process. I also installed at least 2 rads in every room with a floor area of more than 16 square meters. this allowed for even heating albeit less furniture.

So my total surface area of rads is now probably about 3-4 times what I had before, all rads are either double or triple convectors. This allows an extremely low flow temperature of approx 45C on normal days. On very cold days <3C its about 55-60C (this is controlled by the boiler).

So to gain the benefits of weather compensation, I really need to have oversized rads in each room to enable lower flow temps thus keeping the boiler in condensing mode for longer? I have been decorating my house and have changed 3 of the rads (in 3 rooms), but this was before I even considered weather comp. I'm not sure if i have oversized rads now.

You don't need oversized rads for weather compensation. Rads are designed for worse case examples, -3C outside. Less than -3C and they are too large. So, in most of the heating season they are too large and benefit condensing efficiencies. As weather compensators lower the flow pipe temp when the outside temp rises they benefit condensing efficiencies. When room temperature influence is added into the control loop the flow pipe temp dictated by the outside temp may be raised or lower (within a range) to improve matters. Say if the room setpoint temp is 21C and it is approaching 20.5C and the flow pipe temp is 50C, it will lower the flow pipe temp further to stablise at 21C. Above 21C many will cut out the burner, others do not. If flow pipe temp is dictated to be 50C and it raises above 50C the burner is cut out, although a good compensator will modulate the burner down when setpoint is neared.