Commercial Boiler fitted in a house?

[Dan Robinson]

I'm getting the popcorn in.
It's going to be a long night.........

Sadly no.... I have to call it a night soonish... got a bit longer to spend on the little experiment I am running on my own boiler/LLH/controller setup before sending the log files off to the factory.

Then I am off to bed as tomorrow is a long day of fitting a boiler correctly sized for the buildings it has to supply.

Fun though playing with these ********s is, work is work.

 

[AlexCarp]

Why do you think a fricking pipe stat in a LLH is going A) stop a grossly oversized boiler from cycling; and B) fit inside a LLH.

The Boiler is NOT grossly oversized as it can go down to 12 kilowatts. You have been told this and a link given. He just happens to have the instructions in the drawer as well. This one IS on a wind up.

 

[Dan Robinson]

OK then....


Why not put in an Atag Excel 140 or ecoTEC 120?

 

[Dan Robinson]

Google slowed down for you?

The XL140 goes down to about 18kW. Plenty to cope with the hot water as well .

 

[Dean744PiN5]

OP, This is where forums can be dangerous, when you have people like Alex giving incorrect information on a subject they no very little about.
If we day for example the op's house has a mm
Maximum heat loss of 12kw this will be based on a outside temp of -1 or -3 degC this is very few days of the year, most of the time when heating is called for temps will vary anywhere between -1 to 14 degsC where the heatloss of the house could be anywhere between 2kw's and 12.
So on a day where the outside temp is 8degC the boiler will cycle on off because it can only modulate down to 12kw, this short cycling will waste gas and cause premature failure of components , low loss header or not.
Also even your 28mm gas supply could still be undersized, you will need a commercial fitter to install the appliance (and if you think domestic gas engineers are expensive wait till you get a quote from a commercial fitter) same goes for the annual service it will cost more than a domestic boiler as well as on going maintenance and cost of spares, and forget taking a insurance contract out on it as the likes of BG ect won't take on a commercial boiler.
Alex here's a tip on combi boilers, a 40kw combi will have a maximum heat load of around 24kw's for heating mode modulating down to around 6kw's, the 40kw output is just to heat up the water. Here's another tip don't give misinformation on subjects in which you are not qualified to do so.

 

[Dan Robinson]

Off the shelf spares?

Perhaps one of Alex's other persona will be along soon to help?

 

[holty]

alexcrap wrote:

Someone was one about a large buffer to absorb the full 43 kilowatts. Isn't that a thermal store? That would replace the planned unvented cylinder.

ironic you dont know the difference between a buffer vessel and a thermal store. yet your dishing out ****e advice to the OP about using a commercial boiler in a domestic situation. its commercial end of. whatever next... 500l unvented with 60kw boiler in a one bed flat with electric shower. because they were cheap to buy.

 

[ScottishGasMan]

My god Alex pls tell me you dont actually work in the heating buisness.

12kw MINIMUM is no use - ( unless maybe your house doenst have a roof or walls then the heat loss calcs might add up.

To the OP - Do a proper heat loss calc for your house before looking at what boiler you want.

As Dan says, you need commercial for it, LLH - Big Pump and it will turn its self on and off till the death of it. It doesnt light at 12kw. it probably ignites about 30-35kw and holds there for a minute, by which time it will be due to shut off on a severly undersized system

Where a 24kw boiler could heat the place probably no bother and can rate down to 4 or 5kw to maintain that heat (and will still have to shut off and cycle at that)

 

[AlexCarp]

alexcrap wrote:

Someone was one about a large buffer to absorb the full 43 kilowatts. Isn't that a thermal store? That would replace the planned unvented cylinder.

ironic you dont know the difference between a buffer vessel and a thermal store.

I know exactly what they as that was clear I do. And a thermal store IS also a large buffer.

 

[AlexCarp]

12kw MINIMUM is no use - ( unless maybe your house doenst have a roof or walls then the heat loss calcs might add up.

To the OP - Do a proper heat loss calc for your house before looking at what boiler you want.

As Dan says, you need commercial for it, LLH - Big Pump and it will turn its self on and off till the death of it. It doesnt light at 12kw. it probably ignites about 30-35kw and holds there for a minute, by which time it will be due to shut off on a severly undersized system

Where a 24kw boiler could heat the place probably no bother and can rate down to 4 or 5kw to maintain that heat (and will still have to shut off and cycle at that)

I doubt you have read all the thread to write misleading advise. Initially this Dan fellow, backed by others, including you, wrote that the boiler was "too big" and would continually cycle on an off. I looked and found it can run down to around 12 kilowatts, so was not too big at all and would not continuously cycle on and off. The OP already has a 28mm gas supply, so no problems there. Then this Dan starts to try and justify his mistake - or more likely defend his wind up of the OP.

I directed the OP to another thread where I fitted a low loss header and Wilo smart pumps for the heating on a 40 kilowatt boiler. It works brilliantly and has been operating for 6 months perfectly giving a wonderful even heat through the house. The OP can also fit a fixed speed pump for the hot water cylinder off the low loss header as well. All he needs to do is get a pump for the header that will give the minimum flow required through the boiler. Being a 12 to 46 kilowatt boiler that will be domestic sized and not cost a fortune.

I have wiped the floor with this Dan fellow, which is not difficult, and many strangely seem to defend when obviously he is wrong, and who resorts to insults when proven wrong.

If I was the OP, I would fit a low-loss header with a pump pumping through it to give a constant flow through the boiler. Off the header have the heating zone(s) using Wilo smart pump(s). Have one fixed speed pump heat up the DHW cylinder off the header. It is best he looks at my post on the Atmos Intergas thread on a guide on how to do it.

Telling the OP to ditch his new perfectly adequate quality boiler to spend around £900-£1,000 on another boiler is grossly irresponsible advise. I did tell the OP to do heat calculations and I am sure the boiler will match his heating requirements. I doubt his 5 bedroom house will need less than 12 kilowatts of heat. His calcs will determine that.

 

[muggles]

12kw MINIMUM is no use - ( unless maybe your house doenst have a roof or walls then the heat loss calcs might add up.

To the OP - Do a proper heat loss calc for your house before looking at what boiler you want.

As Dan says, you need commercial for it, LLH - Big Pump and it will turn its self on and off till the death of it. It doesnt light at 12kw. it probably ignites about 30-35kw and holds there for a minute, by which time it will be due to shut off on a severly undersized system

Where a 24kw boiler could heat the place probably no bother and can rate down to 4 or 5kw to maintain that heat (and will still have to shut off and cycle at that)

I looked and found it can run down to around 12 kilowatts, so was not too big at all and would not continuously cycle on and off

So what happens when the system demand reduces to, say, 7kw as everything heats up?

 

[AlexCarp]

12kw MINIMUM is no use - ( unless maybe your house doenst have a roof or walls then the heat loss calcs might add up.

To the OP - Do a proper heat loss calc for your house before looking at what boiler you want.

As Dan says, you need commercial for it, LLH - Big Pump and it will turn its self on and off till the death of it. It doesnt light at 12kw. it probably ignites about 30-35kw and holds there for a minute, by which time it will be due to shut off on a severly undersized system

Where a 24kw boiler could heat the place probably no bother and can rate down to 4 or 5kw to maintain that heat (and will still have to shut off and cycle at that)

I looked and found it can run down to around 12 kilowatts, so was not too big at all and would not continuously cycle on and off

So what happens when the system demand reduces to, say, 7kw as everything heats up?

It will cycle. However say if the 5 bedroom house has a heating demand of say 18 kilowatts cycling will be very rare. Modern boilers have timers to reduce cycling effects.

Looking at boiler specs, few boilers run down to less than 6 kilowatt, so cycling is a normal expected rare event and the controls are designed to cope with it. But as I have stated, cycling will be rare as when the boiler starts to cycle the house will be up to temperature and it will be more than likely be off for a considerable period until the large house cools and the boiler comes back in to reheat.

This boiler can run up to 46 kilowatts but that top end power is not used most of the time. Just like large engines in cars.

On a winter's morning when the heating and DHW switch in, the boiler will run up to full 46 kilowatt. The heating pump(s) and DHW pump will extract as much heat from the boiler as they can. The cold system can take all the boiler can throw at it. Near enough full boiler temperature will be pumped to the radiators, which would not be the case with small boiler on a very cold start. The return temperatures will be low keeping the boiler full on at 46 kilowatts for a short period. The boiler will start to modulate down when the return temperatures rises. It will run right down to 12 kilowatt probably quite quickly. So you will have a rapid heat up with this boiler. The top end power can be used very usefully.

You may find the maximum kilowatts can be turned down on the boiler setting maybe making life a little better. However as long as the minimum flow is run through the boiler taking full advantage of the top end 46 kilowatt is well worth it.

 

[Dan Robinson]

You truly are retarded.


I was hoping last night was just a car if your medication wearing off. But salt it seems you really are that stupid.

Or on a wind up like our old friend Big Burner, Water Systems, Dr Drivel et al. Personally I think you misspelled your name

 

[Dan Robinson]

Let's take this slowly.


How many days a year so you think the OPs house will need, for the sake of argument, 18kW of heat input?

 

[AlexCarp]

Vaillant state:
"They are configured to automatically optimise heat and hot water supply according to the demands on the system at any particular time."

I looked at the pump needs. The boiler needs approx. 33 litres a minute running through its heat exchanger. After looking on the Grundfos website and the technical specs on the Grundfos 15/50 and 15/60 domestic pumps it would appear that if the speed control switch is set on position 2 on the 15/50 pump a flow rate of 0.84 litres per second is given, giving 50.4 litres per minute. Maybe position 1 is all that is needed, but a check is needed. I would assume similar to a Wilo pump. So a domestic pump is all that is needed between the boiler and the header. So much for a "large" expensive pump.