Conventional boiler.... comeback Combi all is forgiven!
- Thread starter jdillon
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What do you do when it breaks down and you've no immersion heater to use ? Will the boiler not also rot within 10 years ?
But funnily enough, our HW cylinder is doing fine, and it's more then 10 years old. Boiler's a different matter.
T
TellMeWhy
If it breaks down I am relying on ATAGs service team. Quality products brake down less, that is why people buy them. I did think of having a small electric instant heater under the sink. The type that are in-line with the pipework. I also have an electric kettle.
I have a near enough 100 litre bath capacity, it may be be greater. The combi fills it in a few minutes. I notice no difference to the bath filling speed to when I had a gravity cold tank and copper cylinder. Have a look at a really big combis in operation.
Now back to the 3 bathrooms. If he goes for a large combi. it can fill a bath in a few minutes, then another then another. The three baths will be filled up in about 15 minutes. No waiting for a hour to reheat cylinders. To do that with a cylinder it would need to be 400 litre or over. That is big and expensive. I would only go stainless steel, as copper is false economy. Cheap cylinders are copper. Copper cylinders can last longer in soft water areas, not so in hard water areas, where they are a waste corrosive time.
Then consider all the ugly exposed controls and pumps hanging off it and they are prone to leaks and staining the ceiling below and socks falling behind them never to be retrieved. Another consideration is that would it be too heavy for the floor in his house?
Times move on for the better, go with the flow. Pardon the pun.
T
TellMeWhy
ATAG A350EC. I think that is the right number. It has the gas saver on the flue. It is economical to what neighbours pay in heating bills. It is very quiet when running. My sons old Ariston Microgenus was noisy but reliable. I did consider buying the really big ATAG combi. Then I reassessed and the more efficient, smaller version would do it. I was replacing the bathroom and went for a modern low water content bath. The bath is around 100-120 litres water capacity. It fills up fast enough using the combi. I do not notice any delays to the old gravity water systems I have used. As someone noted in a post I read in this forum, I also ran some 10mm pipe to some taps to reduce the cold lag and fitted flow restrictors on some taps, as the makers recommended, to balance it all out. Having the hot pipes to the taps lagged helps at lot in reducing the cold lag. The ATAG combi also has a plate heat exchanger pre-heat which reduces the lag to no more than a cylinder.
It is worth paying the extra couple of hundred for a quality model. I am beginning to sound like a advert for ATAG. Other companies make big combis as well, but ATAG are quality through and through.
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T
TellMeWhy
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I guess that you mean that you have an ATAG 325ECX which is undeniably a very good boiler (I know, I am one of ATAGs registered service team) but there is no way that I could recommend that combi for any home with more than one bathroom and an en suite..... Any more than that and its a properly installed unvented for me...
Funny that. ..
so am I. And neither would i unless at the specific request of a well informed customer.
T
TellMeWhy
I am with you there, as 1.5 baths with modern low capacity bath as its limit. I do not recommend the this model for 2 baths or more. I have a home with 1.5 baths and it copes very well. Learn form people who walk the walk. It was touch and go to get this or a larger hot water flow model. Balancing the hot and cold water taps and having a 22mm pipe from the water main stop tap only for the cold feed to the combi and some 10mm pipe to taps made a difference to get the best out of it.
An unvented cylinder is dependent on the mains supply as is the combi. A top ATAG will give 25 to 26 litres a minute, you should know that, which is about the same as most unvented cylinders, as they have flow restrictions in al, the valves they have. Believe me I checked all this out.
I seriously recommend that in this case of three baths, if the cold water mains is fine, that he gets the biggest ATAG available, which are about 25 to 26 litres a minutes according to the ATAG web site. I advise that he uses flow restrictors, as ATAG recommend, as the hot and cold taps. A basin only needs about 3 litres a minute for hot and cold taps (6 litres in total). I ran 10mm soft copper from the combi and teeded off to supply both basins. It works great. We only use the basin to wash our hands. The teenage daughter occasionally washes her hair in the basin but I have never heard her complain about poor flow from the basin. A toilet needs about 5 litres flow to fill it, not 20 litres as most have when on mains pressure. The hot showers and bath taps have full flow. The co-incidence of three baths being filled at once is miniscule.
The same approach is used fro electrical circuits. You can have 10 double sockets on a ring. Plug in 20 3 kilowatt fires and turn them all on and see what happens. They size according to "average" use. A home does not operate the same as a hotel in water demand, which sized to maximum use. A home should sized to "average" use.
Read my reasoning above. He can fill three baths consecutively in 10 to 15 minutes with a large ATAG combi. An unvented cylinder can't match that in performance, unless the cylinder is a "large" very expensive heavy job. A large ATAG can even fill two baths simultaneously as both will have about 13 litres a minute, which is fill both in about 8 minutes.
When assessing my house, a gradually realized that an unvented cylinder would be a waste of expensive time and space in the house. Economically it did not stack up. In running costs to the 325ECX it did not stack up.
I don't know if you are just a service man who only fixes boilers. However, installation is a very different matter.
EDIT:
I did have a number of plumbers around and most said put in an unvented cylinder and system boiler. Some boilers they recommended were not the top quality models. One recommend a cold tank, cylinder and power shower pump. He was sent packing. I got a cheaper job with superior cheap to run boiler and saved a lot of money and space. I do not have faith in jobbing plumbers.
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I design, install and repair but I suspect that you are full of it as you profess to be an expert yet cannot give us the model of your boiler and are quoting daft flow figures.... Sure you can shove 26 litres through a 325 but it won't be very warm unless you are feeding it pre heated water...
Doctor Drivel is back
Doctor Drivel is back
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Yes seen and fitted lots of them, dont confuse any high flow combi with a well installed well sized unvented cylinder, theres no comparison.
Any combi fitted in a property with more than one bathroom would just be wrong.
But Atag do a 60kw boiler that does 25 litres a minute that will live longer than a cylinder.
And what's it's minimum flow rate when running the heating ?But Atag do a 60kw boiler that does 25 litres a minute that will live longer than a cylinder.
My guess is that it can't heat anything smaller than a mansion without a significant bypass - meaning that you are installing a system designed not to condense even more of the time than normal. Unless you've doubled up on rads so you can run at lower flow temps.
That's a criticism I have of all the boilers I've looked at the manuals for. Regardless of how low they can range, they still require a minimum flow rate based on max output (or thereabouts). Since combis are almost invariably oversized for the heating (or they are sh*te at making hot water), this means you are automatically installing something that's not suitable for the heating side.
It is a commercial grade boiler that can range down to 9kw and uses a calorifier rather than a plate.
They are not intended for the type of use water systems intended. Rather places that need huge space heating and low to moderate hot water such as a church or office building.
I Wonder if Dr drivel will be back to explain to us numpties a bit further?
They are not intended for the type of use water systems
intended. Rather places that need huge space heating and low to moderate hot water such as a church or office building. I Wonder if Dr drivel will be back to explain to us numpties a bit further?
Back on topic, clearly that cylinder is undersized. A upgrade sounds like its required. To make life better for now, try running that cylinder from first thing in the morning to last thing at night, set it up to come on an hour before you get up, example could be 6:30am till 10:30pm. That way when any water to drawn off the boiler is there to get that cylinder back up to heat.
In the long term, get the boiler upgraded, a modern high recovery unvented cylinder installed, you'll be impressed by the results, plus you can loose that shower pump as unvented offers near mains pressure hot water
A well installed stainless steel cylinder will last for years, the average run time of a boiler is 15 years, but if the system it's attached to is a good on it'll give you many years of fault free service, just make sure you opt for a good brand that's a simple as possible, that way there's less to go wrong.
In the long term, get the boiler upgraded, a modern high recovery unvented cylinder installed, you'll be impressed by the results, plus you can loose that shower pump as unvented offers near mains pressure hot water
A well installed stainless steel cylinder will last for years, the average run time of a boiler is 15 years, but if the system it's attached to is a good on it'll give you many years of fault free service, just make sure you opt for a good brand that's a simple as possible, that way there's less to go wrong.
They are not intended for the type of use water systems
I Wonder if Dr drivel will be back to explain to us numpties a bit further?
I like it
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