We're having some extension work done and it involves replacing the boiler and moving the bathroom. A guy recommended having a Potterton Suprema 100k BTU boiler on the garage wall with a Megaflow next to it and therefore saving space in the house.
Any views on either of these? Or alternatives? Or of having boiler/cylinder in a garage?
Dave
In message , Dave writes
You'd better bookmark my website if you buy a Suprima, do a google on Suprima lockout problems.
Suprima? Avoid like the plague.
Megaflow? Avoid too. Superior alternative is a heat bank. Do a Google on this ng on "pandora", See:
Christian on this ng, is fitting a heat bank right now and using a Worcster-Bosch Greenstar high efficiency condensing boiler to heat it. Both v good choices. A Glow Worm 30SXi is a good boiler and well priced and will mate to the Pandora Heat bank at
- kW - 30.6
- fronst protection
- Fully Modulating Price: £547.00 £642.73 Including VAT & delivery
Another alternative is the Gledhill Systemate with the Switch electric backup.
The Systemate controls the boiler and even has the CH pump inside the casing, complete with frost control. The insulation of these unit is very heavy (even under the cylinders it is insulated) and suitable for garages. It also has "very" smart self adaptive microprocessor based controls.
Also look at the Boilermate, however with the Systemate is better when mated to a condensing boiler as the CH is heated directly from the boiler, so the Glow Worm will modulate the burner down when the house reaches temperature, promoting efficiency. I have a Systemate with a condensing boiler and it works brilliantly.
Just have decent frost protection.
That's odd. I could have sworn that these take up too much space and that you have a combi. At least you did according to a post on 11th September when you had an Ariston Microgenus.
.andy
To email, substitute .nospam with .gl
temperature,
As you want a boiler and cylinder try the Gledhill Gulfstream 2000:
I have two place . In my London pad I have a Microgenus. because of the location the smallest cased combi around had to go in and the Ariston was one of two choices. There are more now. Also a plume could not be tolerated.
The Systemate is the most advanced heat bank around.
The garage might well be fine for the space to put the equipment.
There are cheaper alternatives to the Megaflow which work as well if not better [Albion, Santon]. Megaflow are the leading brand. Most of the other makes have a seperate expansion vessel external to the tank which usual fits on top quite neatly.
The boiler is subject to electronic problems. Other makes and models might have greater reliability and condensing models greater efficiency aswell.
In article , geoff writes
Ditto...proud owner of a Suprima...not:-((....
Oh I see.
Presumably the second one is a backup in case something goes wrong with the first one. Did it come with a three year warranty? :-)
.andy
To email, substitute .nospam with .gl
That is encouraging.
You are right. If something is wrong with one place I can go to the other. No the Ariston was 2 years and 5 years for the plate heat exchanger. Near enough though.
temperature,
Thanks to all - this group may have saved me from making an expensive mistake!
I'd heard of heat banks but didn't know what they were. They look the ideal solution, what's the downside?
Dave S
Compared to unvented cylinders? None really. As long as the flowrate delivers, which it will, it will work very well.
In the unvented cylinder the boiler heats the HW indirectly (just like a vented conventional copper cylinder).
With a thermal store the boiler directly heats all the water in the cylinder. HW is produce when mains cold flows through a heat exchanger in the cylinder and comes out hot. Boilermate is a brand I know of.
There is not a lot to choose between the methods on cost.
Pros for store: Can be legally fitted without a building notice by uncertified installers. Can be fitted with extra heat exchangers to provide lower temp water for underfloor heating or to connect to a solar panel.
Cons for store: Probably doubles the ammount of primary circuit water, so you will need a larger or additional expansion vessel and two lots of corrosion inhibitor and any other chemicals as needed.
Some, e.g., the DPS Pandora and my Systemate heat the store indirectly. Some are actually pressurised, like an unvented cylinder, but these are rare.
Most now have an external plate heat exchanger.
That is not a con?
Larger expansion vessel? only if the whole cylinder is pressurised, which is rare. With the Pandora and Systemate having their own heat transfer coils, this is not a problem. It is also not a problem with an open vented heat bank too. It is true that a couple of 1 litre cans of inhibitor has to be used in the heat banks stored water. Which is a "very" minor cost not worth considering.
A better assessement:
Advantages of Heat-Banks
§ Instant high pressure hot water - When the thermal-store has reached the set temperature, water is delivered instantly at the taps.§ Usable hot water in a matter of minutes - when using a boiler flow/return blending valve.
§ Very high water flow-rate - The high-end heat-banks have a flow-rate up to 45 litres/min.§ Operates on low incoming pressures - Requires a supply pressure of
1 bar to obtain a good flow-rate.§ Long efficient boiler burn - Reduces boiler on-off cycling increasing efficiency. Inefficient boiler cycling is no longer a major problem with boilers with forced flues.
§ Maintains optimum boiler temperature range - If a blending valve on the boilers flow and return is used, it will deliver only the required high temperature to the heat banks, but also maintain the flow/return temperature differential.§ Combines the output of the stored water and the boiler - Some versions can do this.
§ Cylinder may be smaller for a similar performance§ Cylinder at low pressure - Unlike an unvented cylinder it does not store water at high pressures. Although some version do.
§ Fast cylinder recovery rate - When the boiler is connected directly to the heat-bank or an indirect coil, the recovery rate is rapid.§ Legionella bacteria eliminated - The Legionella bacteria cannot survive in the high temperature sealed conditions of a heat-bank.
§ No scale build-up in heat-bank - Containing primary and not secondary fresh water, scale does not build-up inside the heat-bank.§ Cold water storage eliminated - No need for cold water storage tanks.
§ Solar heating storage - Water heated via solar panels may be stored in the heat-bank via a solar coil.§ Easy maintenance - If an external plate heat exchanger requires cleaning or replacing it is a matter of draining down the heat-bank, or closing isolating vales, and unscrewing the plate heat-exchanger. In some rare instances plate heat-exchangers are fitted directly inside the heat-bank preventing on-site maintenance.
§ Easy to improve hot water flowrates - By simply adding additional plate heat-exchangers in parallel, hot water flow rates may be improved. Retrofit additions are possible if extra bathrooms or showers are installed.§ Stored water vessel need not be cylindrical - As no internal coil is used for hot water heat transfer the stored water vessel may be any shape, as opposed to a thermal store which has to be cylindrical for maximum efficiency. This has advantages where space is limited, promoting excellent packaging.
Disadvantages of Heat-Banks
§ The store needs be fully up to temperature to supply baths - Before any hot water is drawn off, the heat-bank must be up to temperature. Many later versions use a blending valve on the return to the boiler to ensure only up to temperature water is pumped into the store by the boiler. This prevents agitation of the stored water, and aiding heat stratification within the store giving useful water at the top of the store within a very shot time. § May not take full advantage of a condensing boiler - Maintaining the stored water at 75o to 80oC results in a generally high boiler return temperature. This will not take full advantage of a condensing boiler, which increases in efficiency with lower return temperatures. With the superior heat stratification of taller cylinders this problem will be reduced. Condensing boilers with a high operational flow and return temperature differential are best suited to thermal stores and heat banks. Fortunately most have a wide temperature differential.§ Lower water temperatures with fast flow-rates - As with Combi boilers, fast flow-rates through the plate heat-exchanger results in lower water temperatures. This is not so pronounced with heat-banks as with thermal-stores.
§ More controls - An extra pump, thermostatic blending valve, flow switch and thermostatic controls are required over a conventional cylinder. An unvented cylinder system requires extra pressure controls.§ Heat loss - Storing water at high temperatures is not efficient as heat loss is more pronounced. Heat-banks are more efficient when constantly used being less efficient when used in houses of infrequent occupation. Some Gledhill heat banks have super high levels of insulation, even under the cylinders, negating this point.
Some, e.g., the DPS Pandora and my Systemate heat the store indirectly. Some are actually pressurised, like an unvented cylinder, but these are rare.
Most now have an external plate heat exchanger.
That is not a con?
Larger expansion vessel? only if the whole cylinder is pressurised, which is rare. With the Pandora and Systemate having their own heat transfer coils, this is not a problem. It is also not a problem with an open vented heat bank too. It is true that a couple of 1 litre cans of inhibitor has to be used in the heat banks stored water. Which is a "very" minor cost not worth considering.
A better assessement:
Advantages of Heat-Banks
§ Instant high pressure hot water - When the thermal-store has reached the set temperature, water is delivered instantly at the taps. § Usable hot water in a matter of minutes - when using a boiler flow/return blending valve. § Very high water flow-rate - The high-end heat-banks have a flow-rate up to 45 litres/min. § Operates on low incoming pressures - Requires a supply pressure of 1 bar to obtain a good flow-rate. § Long efficient boiler burn - Reduces boiler on-off cycling increasing efficiency. Inefficient boiler cycling is no longer a major problem with boilers with forced flues. § Maintains optimum boiler temperature range - If a blending valve on the boilers flow and return is used, it will deliver only the required high temperature to the heat banks, but also maintain the flow/return temperature differential. § Combines the output of the stored water and the boiler - Some versions can do this. § Cylinder may be smaller for a similar performance § Cylinder at low pressure - Unlike an unvented cylinder it does not store water at high pressures. Although some version do. § Fast cylinder recovery rate - When the boiler is connected directly to the heat-bank or an indirect coil, the recovery rate is rapid. § Legionella bacteria eliminated - The Legionella bacteria cannot survive in the high temperature sealed conditions of a heat-bank. § No scale build-up in heat-bank - Containing primary and not secondary fresh water, scale does not build-up inside the heat-bank. § Cold water storage eliminated - No need for cold water storage tanks. § Solar heating storage - Water heated via solar panels may be stored in the heat-bank via a solar coil. § Easy maintenance - If an external plate heat exchanger requires cleaning or replacing it is a matter of draining down the heat-bank, or closing isolating vales, and unscrewing the plate heat-exchanger. In some rare instances plate heat-exchangers are fitted directly inside the heat-bank preventing on-site maintenance. § Easy to improve hot water flowrates - By simply adding additional plate heat-exchangers in parallel, hot water flow rates may be improved. Retrofit additions are possible if extra bathrooms or showers are installed. § Stored water vessel need not be cylindrical - As no internal coil is used for hot water heat transfer the stored water vessel may be any shape, as opposed to a thermal store which has to be cylindrical for maximum efficiency. This has advantages where space is limited, promoting excellent packaging.Disadvantages of Heat-Banks
§ The store needs be fully up to temperature to supply baths - Before any hot water is drawn off, the heat-bank must be up to temperature. Many later versions use a blending valve on the return to the boiler to ensure only up to temperature water is pumped into the store by the boiler. This prevents agitation of the stored water, and aiding heat stratification within the store giving useful water at the top of the store within a very shot time. § May not take full advantage of a condensing boiler - Maintaining the stored water at 75o to 80oC results in a generally high boiler return temperature. This will not take full advantage of a condensing boiler, which increases in efficiency with lower return temperatures. With the superior heat stratification of taller cylinders this problem will be reduced. Condensing boilers with a high operational flow and return temperature differential are best suited to thermal stores and heat banks. Fortunately most have a wide temperature differential. § Lower water temperatures with fast flow-rates - As with Combi boilers, fast flow-rates through the plate heat-exchanger results in lower water temperatures. This is not so pronounced with heat-banks as with thermal-stores. § More controls - An extra pump, thermostatic blending valve, flow switch and thermostatic controls are required over a conventional cylinder. An unvented cylinder system requires extra pressure controls. § Heat loss - Storing water at high temperatures is not efficient as heat loss is more pronounced. Heat-banks are more efficient when constantly used being less efficient when used in houses of infrequent occupation. Some Gledhill heat banks have super high levels of insulation, even under the cylinders, negating this point.
yeah, fsking lockout problems............ need a new reset button soon, almost worn the bloody thing out
In message , David Hemmings writes
Potterton actually changed the reset button to a more resilient design with the later 510216 pcb... I wonder why
I am interested in such a system, as I am currently looking at the options to cope with the intended fitting of a new large bath, beyond the capacity of my existing hot (and cold) tanks which can't even really cope with the existing one.
As my boiler is around 20 years old, replacement is probably due.
I'm not sure I can fit a larger hot tank in the airing cupboard (in the garage with the boiler might work), and would also like to have better shower flow than the present gravity system. Fitting a bigger cold tank might present weight problems, and I am not over keen on pumps.
My existing cold supply seems to have a reasonable flow rate, but appears to be piped in 15 mm from the stopcock, and it is not really practicable to replace this without scrapping the kitchen, which is not planned for a few years yet,
I have to confess that I don't intend to do the plumbing work myself, and wonder how much experience the average installer will have of these less mainstream solutions.
Chris
Thanks, had another lockout this morning and now this evening. Pity can't get an auto resetting one, that you can dial a rest time into, say every 12hours.
Plumber thought he was mustard and sorted everything out by opening up all radiators to full when just my g/friend in the house.
It took me weeks on end to balance all the bloody things to get the right temperature in zones around the house. In retrospect i should have insisted upon thermostatic valves on all radiators (except the bathroom which we selected for the ... dont know the term..... to draw the residual heat from the boiler when the main thermostat cuts it off.
A guy recommended having a Potterton Suprema 100k BTU boiler on th
garage
The Suprema is a great wee boiler...there has been an update on the PC due to intermittant lockout problems...Gas Engineers love to work o them and they are easy to repair and get parts for...also servicing i a real breeze...another equally great wee boiler is the ideal classi range...
-- gastec
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