surely not broadwater farm dan?
Atmos multi Boiler.
- Thread starter Henryv
- Start date
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Dunno whats its called - but I don't relish going there...
DD, you won't get two decent combis for a grand, and two £500 combis are just adding to the chances of the system breaking down. Plus you're doubling the gas consumption and the need to a monster gas line.
DD, you won't get two decent combis for a grand, and two £500 combis are just adding to the chances of the system breaking down. Plus you're doubling the gas consumption and the need to a monster gas line.
D
Doctor Drivel
Dan_Robinson said:
I did say around £1,000. Even if spending £1,500 it is still quite cheap for what they offer: instant DHW, fast bath fillups, natural CH zoning, CH & DHW backup, no bulky cylinders or zone valves hanging off cylinders all over the show, they give rapid heatups first thing in the morning (50kW plus of heat being pumped into the house makes all the difference). Look at what they offer and compare to a system boiler & unvented cylinder in bulk and cost and the two combis win hands down. Combis are cheap as they are mass produced and are in a very competitive market .
You will not need a monster gas supply as a 212 cu/ft per hour meter will cope with two 24 kW combis. A standard U6 meter can cope with 62kW maximum. A 24kW combi consumes approx 82 cu/foot per hour, two of them 164 cu ft/hour, well within scope of the 212 cu/ft of the meter, which has the ability to run on an overload anyway.
You are not adding to the chances of the system breaking down, as the load is spread between the two. A combi serving upstairs will be off most of the time.
You are actually adding to the uptime levels of heat and DHW, as if one combi is down heat and DHW is available in the house - built-in redundancy. You also never run out DHW either, so can be in the shower for ever. The two combined fill up baths very fast. Two 11 litres/min combis will deliver 22 litres/minute. Very good indeed. You could have one 10 litres/min and one 13 litres/min combi.
Note down the pros and cons and it is a hard setup to beat. The only down side is that two services are required, and the cost can be bargained for as the two will be side by side.
I know of quite a few two combi setups and they work very well. I first saw it in France with two Ferrolis coupled up. These had no 3-way valves and were super reliable.
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D
Doctor Drivel
Henryv said:
No. One for one the DHW in one bathroom and one for the other. The outlets are combined to fill only the bath(s). One could do the kitchen tap and one do the utility room tap, so DHW always near the kitchen.
One does CH upstairs and one does CH downstairs. Both on separate clock stats
Simple, very cheap and easy to get high flow, high pressure DHW and a zoned CH system taking up little space giving backup too.
So does the multi
Only if the heating is already plumbed separately. You still have diverter valves in the boilers to fight with, and Honeywell 2-ports are simpler to repair/maintain
Only to the individual areas
2 bulky boxes with all the components crammed in and a bugger to service.
Twaddle I'm afraid. Heating system warm up times would have a neglible difference.
£500 boilers will be cr@p. Clearances top to bottom will take up a similar amount of wallspace as a Multi; and yes slightly less than a system boiler and separate cylinder. They would also cost a lot more to install.
Gas meters have naff all to do with it; it is the pipe sizes; and that depends on system layout.
This is contradicted by your next sentence. But having two low quality appliances installed will have a greater chance of failing than a single high quality appliance (or an unvented cylinder with Immersion) because there is a greater quanity of cheaper parts involved.
So do I and if a house/pair of flats was bought with two separate systems, then I would probably reccomend keeping the that way, but to split a system up on purpose is not, IMHO, a practicle solution.
One of the main problems with getting ideas from different people. Everyone will have their own way of doing something.
D
Doctor Drivel
Dan,
You need to take on board the positive points that are clearly being made. Two combis is clearly something you have never come across or thought about.
The gas meter will more than cope and a dedicated 22mm supply for each back to the meter is all that is needed.
CH Zoning is infinitely more simpler. Have a combi without a 3-way valve and simpler again in controls. Zoning with system boiler is cumbersome, complex and messy. Even zoning with an Atmos has two zone valves hanging off complexing matters.
Two combis will never run out of hot water, as will the Atmos.
Two decent quality combis can be had for £1,500 and less, well below the £2,500 of the Atmos.
It has backup having two boilers, which one boiler will not.
The very fast heat up time, of 50kW being pumped into the house is highly significant - is is twice the heat input to the house than what the Atmos gives.
Two simple combis are no more complex than three zone valves and stats in a cylinder and two heating zone setup.
The electrical control side is s doddle to do. Two sockets (or fused spur), one for each and a simple one wire to a stat programmer, switched on voltage free contacts at the clock. Or use wireless versions to get around Part P.
Reliability is extended as the two combis share the load so are less used.
You need to take on board the positive points that are clearly being made. Two combis is clearly something you have never come across or thought about.
The gas meter will more than cope and a dedicated 22mm supply for each back to the meter is all that is needed.
CH Zoning is infinitely more simpler. Have a combi without a 3-way valve and simpler again in controls. Zoning with system boiler is cumbersome, complex and messy. Even zoning with an Atmos has two zone valves hanging off complexing matters.
Two combis will never run out of hot water, as will the Atmos.
Two decent quality combis can be had for £1,500 and less, well below the £2,500 of the Atmos.
It has backup having two boilers, which one boiler will not.
The very fast heat up time, of 50kW being pumped into the house is highly significant - is is twice the heat input to the house than what the Atmos gives.
Two simple combis are no more complex than three zone valves and stats in a cylinder and two heating zone setup.
The electrical control side is s doddle to do. Two sockets (or fused spur), one for each and a simple one wire to a stat programmer, switched on voltage free contacts at the clock. Or use wireless versions to get around Part P.
Reliability is extended as the two combis share the load so are less used.
D
Doctor Drivel
Dan_Robinson said:
And some ideas are cheaper and better than others.
DD I have indeed come across multiple combi setups. I can think of three that I have worked on in the last few months - although strictly speaking one was a combi/mulipoint set up.
That is how those systems will stay - because it is better for those situations.
Please consider the fact that my customer database is nearly 7000, and I cover a very large area - We look after and install all sorts of systems ranging from little old lady's Medway's and DFE's through to multiple boilers mounted on headers.
I have been talking, on this forum recently, about a large house in Hampstead that has THREE combis, ONE Multi, ONE Mexico and an effing large Megaflo.
Current plans are to change Combis to solar combis, the Megaflo to a twin coiled unit and solar panel. The Mexico to a System boiler and then install a 33kW air-water heat pump and link the systems. It will involve fitting a three phase supply from the street though .
Does that have enough redunancy for you?
That is how those systems will stay - because it is better for those situations.
Please consider the fact that my customer database is nearly 7000, and I cover a very large area - We look after and install all sorts of systems ranging from little old lady's Medway's and DFE's through to multiple boilers mounted on headers.
I have been talking, on this forum recently, about a large house in Hampstead that has THREE combis, ONE Multi, ONE Mexico and an effing large Megaflo.
Current plans are to change Combis to solar combis, the Megaflo to a twin coiled unit and solar panel. The Mexico to a System boiler and then install a 33kW air-water heat pump and link the systems. It will involve fitting a three phase supply from the street though
.Does that have enough redunancy for you?
D
Doctor Drivel
Dan_Robinson said:
Back to the situation in question. A typical 3 to 4 bed house with a bathroom plus en-suite: the most cost effective installation is actually two combis. Been there and priced it all up many times. It always come up tops in many ways. They are cheap to install and run too.
That is how those systems will stay - because it is better for those situations.
Please consider the fact that my customer database is nearly 7000, and I cover a very large area - We look after and install all sorts of systems ranging from little old lady's Medway's and DFE's through to multiple boilers mounted on headers.
I have been talking, on this forum recently, about a large house in Hampstead that has THREE combis, ONE Multi, ONE Mexico and an effing large Megaflo.
Current plans are to change Combis to solar combis, the Megaflo to a twin coiled unit and solar panel. The Mexico to a System boiler and then install a 33kW air-water heat pump and link the systems. It will involve fitting a three phase supply from the street though
Does that have enough redunancy for you?
They need a thermal store in that situation that can take multiple heat sources inc solar and a heat pump. Maybe local plate heat exchangers for DHW on a primary loop from the store, or maybe a secondary (fresh) water loop to all outlets. It is a small commercial setup and should be treated as such.
Utter twaddle I'm afraid.
I think I'll come up with the correct solution after a site meeting with the heat pump guy if that's alright with you...
Thanks for the advice though.
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