Vaillant Ecotec pro 937

[Balenza]

Dan Robinson wrote

The right hand tank ges topped up as the left hand tank is drianed

Er no. The left hand tank is topped up first ,heated top to bottom. When a draw off occurs the boiler delivers its energy direct to the take off section. ie, left tank.

The blending valve is there to effectively increase the store of water to a high volume.

Yep, and combines instantly with the boiler energy to give the higher flowrate. Its a pretty neat design IMO.

 

[Dan Robinson]

The left hand tank is topped up first ,heated top to bottom

Quite right... Not sure where I got that from....

But it is still rated at 30 delta with 20.4l/min flow according to the manual.

 

[Basecoat]

Hi All

I would like views on the new vaillant Ecotec pro 937 boiler. Has anybody had a chance to fit this boiler. Boiler having storage tanks incoporated at back. I am interested in this boiler because of its high output of hot water.

Thanks in advance.

Hi All

Thanks for your response. Having both positive and negative feedback for this boiler has confused me. I emailed vaillant that I need a boiler to heat & deliver hot water to:
4 bedrooms
2 receiption rooms
1 bathroom
2 showers
kitchen sink
washing machine.

The boiler is to be fitted in garage and the ensuite shower is approximately 25 feet from boiler. Vaillant have not bothered to respond. So guys which boiler/system would be ideal. The vaillant catalogue looks nice but is the boiler up to the job its designed for.

 

[ChrisR]

It's not a yes/no answer.
It would work, but a combi's always a compromise. Depends how your individual installation delivers what it's capable of. Good mains supply? How about the plumbing configuration? FLow rates of shower heads? Bath usage?

For best performance, you need a dirty great store of hot water which is pressurised or pumped. But for that you need the space.

 

[Dan Robinson]

Try this

 

[simond]

Interesting Dan

Where is it made?

The documentation makes a few statements that give me concern. For instance, there is an FAQ; 'why do we not fit an immersion to our cylinder?' and their answer is that their unit is so reliable it is not necessary and also that immersion heaters are themselves unreliable.

Similarly, they claim that their unit is 'unique' to mix condense and emergency discharge in one single outlet. This is just not true, take the Viessmann 333 for instance.

My feeling is that if I can immediately see one dubious and another false claim in their two page brochure, how much should I take at face value?

 

[ChrisR]

Note the award was 2001, does that predate the Viessmann?

They don't say anything about immersion heaters being unreliable. Read...

I would like to have one one in a thing with a store that big, though.

CONDENSING
GAS BOILER
In centre of hot
water tank

That could be fun to maintain!

 

[Dan Robinson]

Theyt are made in Holland by Daaldrop. Well we've fitted quite a few and only had to worry about a couple of duff domestic EV's - small 5 litre jobs.

When the 'unique' claim was made this was the only boiler that could mix condensate and safety discharge (the D3 as well as the primary water safety discharge). I saw the letter from the ODPM allowing them to do it. Subsequently others were allowed to follow. I do agree that they are desparately in need of updating their literature but Atmos have been concentrating resources on the Intergas range.


I wouldn't have fitted one in my own home (as it's totally overkill) if I didn't rate it. Remember ALL manufacturer's claim their products are totally reliable, and considering the number of dead immersion thermostats and elements, Vaillants, Glowworms, Sauny's and Vokera's that crop up over the course of a year I would tend to agree.


I also find the anti-theft locking bar amuzing - you would have to be a very desparate ***** to try and lift one of these into you Pikeymobile. They're heavy b@stards!


They like accumulatros as well Simon .

 

[Doctor Drivel]

Doesn't work like that. The 15 litre store is actually 2 7.5 litre stores. The stored hot water is blended and not necessarily drawn from both tanks, depending on flow rate the boiler decides how much and what tank it comes from. Only if both tanks/store completely depletes are you left with the 15.2 l/pm flow rate.

See:
http://tinyurl.com/29judl (the manual)

No blending valve, and tanks look like water is stored at the outlet temperature. If stored at a higher temp then more energy is stored, but this will be too hot for the tanks.

I can't see where they get 20 litres/min figures from, (200 litres in 10 mins) when it only stores 15 litres of water at outlet temperature. This store of water will deplete as the cold mains runs though it. ~15 litres/min the burner gives, so 150 litres in 10 mins. Add the 15 litres and that is 165 litres/min.

I'll need some convincing. Anyone want to?

 

[gas4you]

As its you No You have missed the main concept of this design.

Stick to your thermal stores, no one can argue with you about them

 

[penpusher]

I put one in a customers house last week and it's the absolute dogs

They had an old Bermuda 551 and they tell me that they are over the moon with it.

Apart from the initial piping of the acustor its a doddle to install too.

 

[Doctor Drivel]

Stick to your thermal stores, no one can argue with you about them

So you don't know then

 

[gas4you]

I know all there is to know about Vaillants, well the new ones, as I live and breathe them

But whatever anyone replies to you on here you will google and find a diversve reason to tell them that they are wrong.

So, as i am not prepared to descend into another pointless post/argument with you I feel there is no point in wasting my time with an intelligent response, apart from this one.

Your previous posting history has turned a lot of us against you I'm afraid.

I acknowledge your skills with the thermal store systems but not with anything else.

 

[Doctor Drivel]

I know all there is to know about Vaillants, well the new ones, as I live and breathe them

You should know then.

But whatever anyone replies to you on here you will google and find a diversve reason to tell them that they are wrong.

So, as i am not prepared to descend into another pointless post/argument with you I feel there is no point in wasting my time with an intelligent response, apart from this one.

If you know how this combi operates then please tell us all. The manual does not explain in any detail the operation.
What temp' is the water stored at?
How does it blend down the temp - if it does blend down?
etc?

You are a Vaillant expert, not me. I am an engineer who understands drawings and the likes and understands descriptions too. Just explain how it works to magically get 15.5 litres/min into 20 litres/min by adding a 15 litre tank on the back.

Just musings from me:
Most combis do not condense when producing DHW. The return from the plate back to the main heat X is kept high (lowering DHW flowrate) to ensure the delta T of the main heat X is kept within temperature spec. They also skimp with the plate heat Xs, not extracting enough heat from the boilers main heat X (they want t keep the plates small to save space too).

They can fit a larger plate heat X. Feel the 100 kW plate heat X on a heat bank and the returning water to the store is "cool", very cool, far cooler than what is on combis. Vaillant by using the tank ensure that the returned water to the plate is "cool" as the cold mains enters at the tanks bottom and this is pumped immediately back to the plate heat X. That adds efficiency and raises the flowrate. How much I don't know, or whether the rise is significant.

If the mains water tmep is 5C, tye return temp to the plate heat X maybe 7C (mixing in th tank). Raises the temp 35C to 42C. This is pumped to the top of the tank (too cold for the outlet). This may mix with the hotter water in the tank blending up.

There is flow guage that tells the pcb the cold mains pcb flow. The bottom of the tank temp is known, as is the temp from the plate to the tank. "IF" the tank pump modulates then the temp of the water going to the tank can be controlled. "IF" the water in the tank is stored at "n" temp, then the temp of the water to the tank can be controlled as they know what temp it should be to get the correct outlet blend temp. There is no temp sensor on the DHW outlet which I find odd.

 

[Doctor Drivel]

But whatever anyone replies to you on here you will google and find a diversve reason to tell them that they are wrong.

Far too many go by old wives tales and rule of thumb.