Vaillant 837

[mick2877]

I have decided on a Vaillant boiler after talking to several owners. I have a three bed one bath house and have been recommended a 831, is there any benefits of having an 837 fitted ?

 

[Agile]

It is a higher power boiler and will heat more hot water.

It is a higher power boiler and will cycle on/off for most of the time on heating.

A cylinder and a 12-15 kW boiler would be more efficient and provide a greater hot water flow rate!

Tony

 

[gas4you]

If you prefer baths then the 837 will fill the bath quicker.

If you have mainly showers, then unless you have a drencher type shower, stick with the 831.

The 837 also sticks out from the wall another 3"

 

[Biggles..]

It is a higher power boiler and will heat more hot water.

It is a higher power boiler and will cycle on/off for most of the time on heating.

A cylinder and a 12-15 kW boiler would be more efficient and provide a greater hot water flow rate!

Tony

range rated through D0 will stop the cycling.

Give over with the must fit a cylinder rubbish, new heat only/system boiler,upto date high recovery cylinder,possibly tank and bye law kits plus controls package is more trouble and cost than its worth in 9 out of 10 cases.

831 is about 12 litres,837 is 16 litres per min,theres hardly any difference in the grand scale when it comes to price as lng as your cold main is sufficient to give those flow figures.

Standard LP hot water is 18-25litres, hardly that much better, but you have an electric immersion backup if the boiler fails. Combi your down to using the keetle.

Lee

 

[mick2877]

my flow rate is 14ltrs a min with 3.5 bar pressure is that enough for the 831 ?

 

[gas4you]

Yes thats plenty for an 831 but not quite enough for the 837.

Stick to the 831. Less chance of your gas pipe having to be upgraded so much as well.

 

[spikebmth]

I think its a personal opinion, I;d recommend the 837, as about 150 more which isnt so much in the whole scheme of things.

As stated, will give a better flow rate, filling your bath quicker.

 

[Agile]

range rated through D0 will stop the cycling.

Lee

A typical three bed semi needs about 10 kW when its 0° outside and far less for most of the year. About 5 kW when its 10° outside.

Do you think a 31 kW or 37 kW boiler is going to modulate down low enough?

My book says the 837 only goes down to 12 kW which is probably more then the house needs even when its -1° outside !

Tony

 

[mick2877]

will the 831 be okay to use with a grohe euphoria system shower. will the shower go cold if a hot tap is opened downstairs ?

 

[gas4you]

Any combi will only work efficiently for hot water with one outlet on at a time.