Hi I am replacing my conventional boiler with either a Veissmann 100W or 200W system boiler im just wondering whats the difference between them? I have a semi detached house 10 radiators, 2 bathrooms, 1 powershower. Any help or advice would be appreciated thank you
Viessmann system boiler 100W or 200W
- Thread starter Mojo12345
- Start date
Sponsored Links
https://www.viessmann.co.uk/products/gas-boilers/gas-condensing-boilers/vitodens
the 200 has a touch screen and is compatible with veissman own smart heating control via wireless, it has a better modulation ratio, it is a newer model than the 100.
either will work if the correct KW is chosen.
what is the price difference?
the 200 has a touch screen and is compatible with veissman own smart heating control via wireless, it has a better modulation ratio, it is a newer model than the 100.
either will work if the correct KW is chosen.
what is the price difference?
Sponsored Links
You are getting very confused...the new blue cylinder is a traditional vented cylinder.
It's cold inlet will be gravity fed from the large water cistern in the roof.
In case of overheating steam is allowed to boil off by a vent pipe that rises from cylinder top connection, vertically up and loops over the cistern where the pipe end just dips below the cistern lid.
Your taps (normally except the kitchen cold) are at low pressure governed by the height from tap outlets to cistern water level....hence shower pumps are often required.
I hope the cylinder immersion heater has been installed and can be operated if the boiler is out of action.
Your boiler system is presurised and hence you have the red expansion vessel..the compressed air inside the vessel creates a static pressure in the system (to allow you to bleed air from the system) and (since air is compressible) accommodates the small extra volume of water when the system is up to temperature and the water expands by a few %.
I strongly advise you not to get a system boiler. With your size of property (and no doubt poorly insulated and a highish heat load) I would advise a regular (aka heat only) boiler.
This allows you to add a more appropriate sized expansion vessel. You are also not tied to the boiler manufactures choice of pump (and often exhorbitant cost of replacement).
System boilers are more suited to new build properties with small heat loads...where the expansion vessels only need to be of small volume.
You must understand that all boiler manufacturers reward installers to promote their brand...and as their customer are rarely the priority. I would never recommend a Viessmann. They are over complex and often experimental boilers with the customers as the test bed. When the warranty is voided (always a possibility especially if the system water is not spotless) you'll find Viessmann spares are amonst the most expensive in the industry. They are rarely stocked at merchants so parts are via couriers. Much of the trade also refuses to work on them due to the hassle of spares availability and prices.
With that cylinder you may only need to allow a few kW to heat it as the calorifier (the coiled tube inside that dissipates the heat from the boiler water) is relatively small (compared to high recovery cylinders/unvented cylinders).
See if the coil rating is written on the side. There's no sense in putting a larger than necessary boiler in.
It's cold inlet will be gravity fed from the large water cistern in the roof.
In case of overheating steam is allowed to boil off by a vent pipe that rises from cylinder top connection, vertically up and loops over the cistern where the pipe end just dips below the cistern lid.
Your taps (normally except the kitchen cold) are at low pressure governed by the height from tap outlets to cistern water level....hence shower pumps are often required.
I hope the cylinder immersion heater has been installed and can be operated if the boiler is out of action.
Your boiler system is presurised and hence you have the red expansion vessel..the compressed air inside the vessel creates a static pressure in the system (to allow you to bleed air from the system) and (since air is compressible) accommodates the small extra volume of water when the system is up to temperature and the water expands by a few %.
I strongly advise you not to get a system boiler. With your size of property (and no doubt poorly insulated and a highish heat load) I would advise a regular (aka heat only) boiler.
This allows you to add a more appropriate sized expansion vessel. You are also not tied to the boiler manufactures choice of pump (and often exhorbitant cost of replacement).
System boilers are more suited to new build properties with small heat loads...where the expansion vessels only need to be of small volume.
You must understand that all boiler manufacturers reward installers to promote their brand...and as their customer are rarely the priority. I would never recommend a Viessmann. They are over complex and often experimental boilers with the customers as the test bed. When the warranty is voided (always a possibility especially if the system water is not spotless) you'll find Viessmann spares are amonst the most expensive in the industry. They are rarely stocked at merchants so parts are via couriers. Much of the trade also refuses to work on them due to the hassle of spares availability and prices.
With that cylinder you may only need to allow a few kW to heat it as the calorifier (the coiled tube inside that dissipates the heat from the boiler water) is relatively small (compared to high recovery cylinders/unvented cylinders).
See if the coil rating is written on the side. There's no sense in putting a larger than necessary boiler in.
viessman have won the which awards for quality product, also which boiler would you recommend? thanks and yes i do get confused as i am not a plumber or gas engineer, viessman has stainless steel heat exchanger which are excellent i have heard
should i stick with a valiant? cheers
i was thinking veissman 100W 26 kw open vented regular
should i stick with a valiant? cheers
i was thinking veissman 100W 26 kw open vented regular
Last edited:
From another thread "I'd be wary of anything 'Which' recommend, there subscriber base isn't a snapshot of the average 'Joe Public'"
Read more: https://www.diynot.com/diy/threads/...r-recommendation-thread.550312/#ixzz6UG97vMvc
Quite a few pros on here rate the intergas range of boilers highly, which also have stainless heat exchangers, I believe.
Stainless Heat Exchanger, you say?
I think not.
It's so easy to read something like this, posted by someone who clearly doesn't know the facts, and hence to to be misled.
Personally I take notice of professionals on here (Muggles or Ian to name just two) who post factual information from their perspective as tradesmen who have hands on experience ... as opposed to some others who confidently post stuff that they "believe" is correct or that they've Googled and taken as "Gospel"
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
