Advice for selecting new boiler

[moody_gaz]

Hi everyone!
I am currently in need of a new boiler as my aging (19yr old) vaillant combi is breaking down gradually. I have a 4 bed house with 1 bath and 1 en-suit, now wife and I have got away with having to take a shower when the other is not using the other shower or any other appliance. but with two kids growing up I would like something capable of running two showers at once. I like the idea of a 'never ending' supply of hot water so these storage combis seem to fit the bill on that score. Is there any downsides to these against a storage tank and system boiler?, also there seems to be different ways of heating for instance the ACV heatmaster tank in tank idea or the Atmos Multi boiler!. I would also like something that would last another 15yrs or so before gradually giving up the ghost! So with so many choices out there can anyone point me in the right direction?

 

[wnjswozo]

vaillant 837 eco tec,top boiler

 

[radswilldo]

I'd go with vaillant ecotec 937 as you have 2 showers, so long as you have the working pressure. There are other options but I guess you dont have the space

 

[moody_gaz]

I have 2 bar static pressure and approx 24ltrs/min flow. What are the breakdown statistics like on these, its seems a good buy when compared with the viessmann vitodens 333 but you get a 5 year guarentee with these. I could make room for any type of system, I would just like to get the best for the type of application needed without throwing money away of course ( can't see the point of buying a roller when a mini would do the job perfectly well, although I would like to keep it for more than 3 years!)

 

[radswilldo]

Its working pressure you will need to read. The 937 requires 1.3 bar for optimum performance while the 837 needs 0.75. Discount the 837, its a stored combintion boiler you need, as your replacing a combi, other options are not economical, then again I dont now what your pepared to do. Get the working pressure, but I'd be surprised, considering your static pressure, if the working pressure is decent enough

 

[moody_gaz]

hopw do I test the working pressure?

 

[radswilldo]

Attach pressure guage to washing machine valve, the reading shown is static, open cold main on kitchen sink, observe guage, that is working pressure.

 

[moody_gaz]

cheers! I'll try that tomorrow

checked pressure today, static pressure varied from 2.3 bar to 2 bar, working pressure ( using utility tap which dropped the most pressure) varied from 1.4 bar to 1.7 bar during the day. So I suppose I could use the vaillant 937, this seems a good buy when stacked against the viessmann vitodens 333, and Atmos multi as these are approx 700 quid (and over) more than the 937.