System Boilers with Megaflow Cylinder

[stiler]

A question for the Heating Engineers out there familiar with Megaflow/Santon Systemfit Cylinders.
I have one of the pre-plumbed Megaflow Systemfit cylinders waiting to be installed but have now decided to replace my old boiler (which was not originally planned) with a new one at the same time. I've been looking around and have decided upon one of three makes of boiler, ATAG, Remeha or Viessman. I've noticed while looking that the System boilers that they tend to offer better/more advanced technology's over their Regular boiler counterparts, for example while all of the above offer makes offer Weather Compensation in the models I'm looking at they all appear to have more sophisticated Weather Compensation on their System boilers than they do on their Regular boilers (it's not just WC but quite a bit of other tech as well).
So my question is bearing in mind I already have the pre-plumbed cylinder how much re-engineering will be required to use a system boiler over a regular boiler? Just so I get it clear in my head and so I don't go out and get new boiler that is going to to cause a lot of re-engineering and cost a fortune to have installed am I right in thinking that in laymen's terms it's basically just going to be a case of having the cylinder pump removed and then it will we able to support a System type boiler??
If the cost of modification is going to outweigh the benefits of the additional features that I'll just have to bight the bullet and live with a Regular boiler.
Just one further question, most the the Regular boilers are Open Vent (this is another reason I would prefer a System Boiler) but I presume these can be sealed aswell?? as I really would like to do away with an FE tank for the boiler.

 

[Agile]

All the OV boilers can be used on a sealed system.

I think that the ( or perhaps "a" ) Viessmann system boiler includes a diverter valve to divert the boiler output to the cylinder. You still have to use a motor valve on the cylinder as its part of the safety devices.

Obviously its difficult for me to understand why you ever ordered a preplumbed cylinder but its not any problem not to use a built on pump.

Tony

 

[Happyplumber]

A very important question is the size of the system,how many radiators you have ,the expansion vessel inside system vessel may not be large enough

A system boiler is usually whichever manufacturer you use their equivalent combination boiler with certain parts removed.

The conventional boiler is totally different and built as standalone unit and can be used on conventional systems wether they are open vent or fully sealed ,because the expansion vessel has to be sized according to the system you can have alot more flexibility.

There is no pump inside either, so this can be sized accordingly to the needs of the system alot of flexibility in this boiler.

When it comes to parts they are generic ie you can choose items off the shelf eg grundfos pump and honeywell valves and not tied down to a certain manufacturer and their ridiculous prices

Its your money so your choice ,spend wisely and think of the future maintenance

 

[stiler]

Many thanks for your input guys.

It's only the extra tech that has me hesitant otherwise I wouldn't hesitate to go for a Regular/Heating boiler over a System boiler as I believe they would be easier and cheaper to maintain with the use of non oem parts etc than a System type would.
I just understand why Regular/Heating boilers seem to lag behind the System type in features in their features.

 

[powell30]

Be careful here, removing the pump maynot be possible as it is part of the overall controls and under G3 maynot be allowed. Plus it may invalidate your warranty not using the supplied components

 

[Happyplumber]

If you s ask me as professional,what i would have in my own house then it would not be a cut down combi,which is what a system boiler is constructed from .I would prefer to have a regular or conventional heat only boiler,apart from weather compensation what are these bell and whistles you hoping for in a system boiler

Weather comp is available on conventional boiler as well by the way

Thats my personal and professional choice


Thank ya very much

 

[stiler]

Ahh okay but surely removing the pump will just revert it to being like buying a cylinder only?
Decisions, decisions. With a bit of shopping around there appears to be very little difference in price between System and Regular/Heat only boilers but they System Boilers have all the latest tech and more bells and whistles.

So another option that occurs to me is to flog the Systemfit on ebay and buy a OSO SuperS cylinder and a all singing and dancing System boiler....now I'm more confused then ever as what to do.

 

[powell30]

No. G3 states that if the system is a 'pack' then the controls must be fitted complete......no mix and matching. I am unsure if this would apply to the pump but it is supplied as complete so swapping out the pump, reworking the pipe work to accomadate the system boiler pump would invalidate the warranty for sure and maybe illegal........your call

 

[stiler]

Many thanks guy's appreciate all the help/advice. Look's like it going on ebay then.

OSO Super S and ATAG A320S it is.

 

[Agile]

Any unvented must be installed by a qualified person who would reach a decision on whats possible or not.

A system boiler could modulate the pump which is not possible on a regular boiler.

Not many modulate the pump though!

Tony