Megaflow cylinders
- Thread starter theleg
- Start date
They give you mains pressure hot water like a combi, but stored so you have much better flow rates. Im pretty sure megaflow is just a brand name for an unvented system.
Im currently deciding what to fit, but leaning towards the combi purely for the efficiency and low amount of space required.
Im currently deciding what to fit, but leaning towards the combi purely for the efficiency and low amount of space required.
Last edited:
You (most commonly) get two types of gas fired central heating / hot water systems, direct and indirect.
They both heat the radiators in the same manner but differ in the way hot water is delivered to taps.
In a direct system you have a combi boiler which produces hot water on demand ie. it physically heats the water when a tap is opened.
In an indirect system your boiler is used to heat up a big tank of water (the cylinder). This tank then provides your hot water. The advantage of this is that if you have multiple bathrooms a combi might not be able to provide enough hot water for simultaneous showers. The downside is if you use up all the hot water you'll be taking a cold shower or waiting 15+ mins for the water to heat up again! Mind you this shouldn't be a problem if the system is correctly sized.
Another advantage of indirect systems is you can fit an electric immersion heater to the cylinder. This allows you to still have hot water in the event of boiler breakdown.
You'd also need an indirect system if using solar panels (thermal) to help heat your water.
Megaflow is one of a number of manufacturers of cylinders.
Have you got any problems with your system you are looking to address?
They both heat the radiators in the same manner but differ in the way hot water is delivered to taps.
In a direct system you have a combi boiler which produces hot water on demand ie. it physically heats the water when a tap is opened.
In an indirect system your boiler is used to heat up a big tank of water (the cylinder). This tank then provides your hot water. The advantage of this is that if you have multiple bathrooms a combi might not be able to provide enough hot water for simultaneous showers. The downside is if you use up all the hot water you'll be taking a cold shower or waiting 15+ mins for the water to heat up again! Mind you this shouldn't be a problem if the system is correctly sized.
Another advantage of indirect systems is you can fit an electric immersion heater to the cylinder. This allows you to still have hot water in the event of boiler breakdown.
You'd also need an indirect system if using solar panels (thermal) to help heat your water.
Megaflow is one of a number of manufacturers of cylinders.
Have you got any problems with your system you are looking to address?
Thanks for the info guys.
I bought my place a couple of years ago now but ive been working elsewhere so never really had the time to look at it properly. It is a proper bodge DIY job by the previous owners. It actually flooded the ground floor because of a badly capped off 'something' that the guy had removed when he left.
Have an old boiler with a water cylinder upstairs, which means its indirect right? and with a water tank in the loft. However, the house is a converted bungalow which means the water tank in the 'loft' is only really a foot above the cylinder. The water pressure in the showers and taps is pretty awful. There are several small pumps which are sitting in what appear to be plant pot bases lol. Just loose on the floor in the airing cupboard. These appear to have been used to provide water to the bathroom in the extension. The shower attached to the bath in there has amazing pressure incidentally, but the shower cubicle in the same room is a dribble. Its quite confusing.
I have a megaflow cylinder just sitting around in a container and was wondering if i could incorporate it into the system to solve the pressure issue.
Its only a 3 bedroom bungalow, would one of these cylinders be overkill? Would I be better off just getting a combi boiler and doing away with the existing cylinder in the airing cupboard?
These are the questions running around my mind
I bought my place a couple of years ago now but ive been working elsewhere so never really had the time to look at it properly. It is a proper bodge DIY job by the previous owners. It actually flooded the ground floor because of a badly capped off 'something' that the guy had removed when he left.
Have an old boiler with a water cylinder upstairs, which means its indirect right? and with a water tank in the loft. However, the house is a converted bungalow which means the water tank in the 'loft' is only really a foot above the cylinder. The water pressure in the showers and taps is pretty awful. There are several small pumps which are sitting in what appear to be plant pot bases lol. Just loose on the floor in the airing cupboard. These appear to have been used to provide water to the bathroom in the extension. The shower attached to the bath in there has amazing pressure incidentally, but the shower cubicle in the same room is a dribble. Its quite confusing.
I have a megaflow cylinder just sitting around in a container and was wondering if i could incorporate it into the system to solve the pressure issue.
Its only a 3 bedroom bungalow, would one of these cylinders be overkill? Would I be better off just getting a combi boiler and doing away with the existing cylinder in the airing cupboard?
These are the questions running around my mind
Yep, you have an indirect system.
These are split into two types vented and unvented. Yours is a vented system which is the older design. It relies on mavity to get the water from a tank in the loft to your taps and as you find is often problematic when it comes to water pressure/flow.
Modern systems are unvented. They are fed directly from the mains and consequently have much higher pressure/flow rate (unless you have abnormally low water pressure, but thats a whole other issue). These do away with the loft water tank.
I doubt changing the cylinder would make any difference at all apart from bringing the water up to temperature faster (larger heat exchanger and not scaled up). It certainly wouldn't make any difference to your pressure issues. You'd have to check compatibility. If your megaflow is an unvented design I suspect it wouldn't have the right connections to work in a vented system.
Your cheapest option is to investigate why the booster pumps are working for the bath but not the shower. I don't know whether it is a pressure sensor or water flow physically turning the pump's impeller that triggers them but it is certainly flow. Maybe the shower doesn't produce enough flow to trigger the pump? You could try removing the shower head and pipe and see if that makes any difference. Or maybe one of the pumps is for the bath and other the shower and one isn't working.
Ultimately a new Combi Boiler and retiring the water tank + cylinder is the best job though of course not cheap.
These are split into two types vented and unvented. Yours is a vented system which is the older design. It relies on mavity to get the water from a tank in the loft to your taps and as you find is often problematic when it comes to water pressure/flow.
Modern systems are unvented. They are fed directly from the mains and consequently have much higher pressure/flow rate (unless you have abnormally low water pressure, but thats a whole other issue). These do away with the loft water tank.
I doubt changing the cylinder would make any difference at all apart from bringing the water up to temperature faster (larger heat exchanger and not scaled up). It certainly wouldn't make any difference to your pressure issues. You'd have to check compatibility. If your megaflow is an unvented design I suspect it wouldn't have the right connections to work in a vented system.
Your cheapest option is to investigate why the booster pumps are working for the bath but not the shower. I don't know whether it is a pressure sensor or water flow physically turning the pump's impeller that triggers them but it is certainly flow. Maybe the shower doesn't produce enough flow to trigger the pump? You could try removing the shower head and pipe and see if that makes any difference. Or maybe one of the pumps is for the bath and other the shower and one isn't working.
Ultimately a new Combi Boiler and retiring the water tank + cylinder is the best job though of course not cheap.