35KW Viessmann Vitodens 100W

or

37KW Vaillant ecoTEC Plus 937

which one to go for?

Worcester Bosch 😉

none of the above, boiler and unvented cylinder.

(didn’t want to disappoint!)

Worcester Bosch CDi

We have the Viessmann 100, been fitted for 2 years now. no problems to report. very quite, VERY efficient. it was the stainless heat exchangers that drew me to this boiler over the Worcester, that and the 5 year warranty that at the time was rare with other marques.

We’ve had a vaillant 937 for 5 years now, some early issues as it was new to the market but faultless since. Worth looking at the minimum water pressure levels if you’re considering a Worcester, the 937 requires a minimum pressure of 0.5bar to achieve its max water delivery, the equivalent Worcester at the time was 2.5bar iirc.

I went Worcester Bosch and it was excellent. Will be using them again in the new place!

Worcester Bosch CDi

had a couple of the plumbers saying that they have good parts availability for a reason, also very “electronic” so if something pops it tends to be expensive and they are difficult to work on

Veissmann have an excellent reputation for reliability. Remeha Eco plus are also worth a look. Make sure your plumber is familiar with whatever you choose though

If I had to though would be a Worcester

Vallient ecoTec plus here. Gas man (not he installier btw) says its one of the best around. It has a seting that keeps a small resevoir of hot water at temp so you never have a warm up period as you turn a tap on.

Marvellous.

Worcester Bosch. I don’t own one but if I could afford it’d be one of those. DONT buy anything on sale in B&Q.

“It has a seting that keeps a small resevoir of hot water at temp so you never have a warm up period as you turn a tap on.”

My boiler has this feature , ace – but you still need to displace the volume of cold water in the pipe …..

any other thoughts on the two boilers?

Both are quality products, I have more personal experience on Worcester boilers.
Considering I fit more of them (about 95% of my gas boiler installs) I seem to repair far less than any other make. Others will probably tell you they hate Worcester etc, but generally I can find little fault with them. spares are readily available too.

none of the above, boiler and unvented cylinder.

As an ignoramus, why?

spares are readily available too.

I can still get spares for my 30 year old Potterton…..

Nicko – back up for hot water as it will have an immersion heater fitted so you will have hot water if boiler breaks down. Far superior flow rates than all but the biggest floor standing combi (providing incoming water main is sufficient), allowing better choice of taps and multiple outlets.

Flaps – yes spares are available for old boilers, but you might wait (you also probably have a very simple boiler with not many spares required), Worcester are usually next day.

Been warned off Vaillant & GlowWorm boilers by several plumbers/installers as their customer service and reliability is dreadful apparently.

We went for a Worcester Bosh CDi about 18 months ago and have had no problems since. Also a lot more economical than the old WB it replaced.

Many Worcester Bosch combi’s come with a 7 year warranty!

you also probably have a very simple boiler with not many spares required

Yep, it’s almost clockwork so nice and easy to work on 😉

trail_rat – Member

My boiler has this feature , ace – but you still need to displace the volume of cold water in the pipe …..

Indeed, I have the advantage of my boiler being upstairs about 18″ away from the bath/shower on the other side of the wall…

back up for hot water as it will have an immersion heater fitted so you will have hot water if boiler breaks down. Far superior flow rates than all but the biggest floor standing combi (providing incoming water main is sufficient), allowing better choice of taps and multiple outlets.

Yep, you’d keep the immersion heater as backup; but you don’t think the theoretical benefit of only heating up the hot water you need (combi) outweighs any downsides of flow, taps etc? For a 2-person house, say?

I would say that having hot water while you wait 2 /3 days for a boiler repair outweighs that.

Also modern cylinders are very efficient both regarding heat up and standing losses. Every time you turn a tap on the boiler fires regardless of how much water you need, then that water cools in the boiler if you don’t need it for a while. This happens a lot with combis, especially if someone turns a tap on then doesn’t wait for the warm water to get to them.

More to go wrong in a combi therefore shorter lifespan.
potential waste of water running all that cold away first.
who says that in a year or twos time personal circumstances change, want to add a bathroom / en-suite etc, cylinder will probably have capacity.
Rubbis flow rate from standard combis when incoming main is cold in winter and you want a bath that is more than about 40 deg.

Don’t get me wrong combis have there place (I have one sadly, but will link it to a cylinder when I add the extra bathroom) and I fit a fair few but I think they are oversold by the industry.

Been warned off Vaillant & GlowWorm boilers by several plumbers/installers as their customer service and reliability is dreadful apparently.

Their Technical Help desk used to be very. very good. The only issue with the older Vaillant tech help guys was, that if they asked you for a reading, or the results of a check that you should have done, and you hadn’t, they’d tell you to go away and come back when you’d tried to mend the thing. Which is fair enough if you ask me!