An interesting theory but I think you'll find it won't work as you expect it to. If it only operates once the tap is switched on, you will still have to draw off the same quantity of cold water before you get hot to the tap, as the amount of cold water in the pipe between the cylinder and your tap will not change. It would reduce the time required for the hot water to reach the tap by increasing the flow rate, but it would do this whether you installed the secondary loop or not, making the loop redundant. In fact the loop may hinder you as some water would be forced back to the cylinder rather than out of your tap, and you would also end up with a loop of warm water that then goes cold, thereby wasting energy heating water you're not going to use.
So, in short, it depends what you're trying to achieve. If you're trying to save water you need a properly-installed secondary loop with a bronze pump. This would either run constantly or you could feasibly have it running off a timed switch that you operate by the desired outlets before you open the tap, although to my mind that's a bit of a faff.
If you're just trying to increase flow to the taps then the whole house pump would be a good option but it's not going to save you any water and the secondary return is pointless.
Hope this helps
Thank for the input Muggles. What I am trying to achieve is to reduce the time for hot water to get to the taps. You state, "you will still have to draw off the same quantity of cold water before you get hot to the tap," This I disagree with. If a tap 20 foot away is opened then the pump kicks in and it can shift 23 litres of hot water a minute around the loop. This is around 0.4 litres a second. It will be a matter of seconds before hot water is at the taps, and a saving of water and the pump only run when needed, so saving electricity. Simple installation as well. This means a permanently hot/warm loop is not required. OK there will be more of lag than having a permanently hot loop, but not that much to worry about.
These pumps are quite cheap, about £80-90 cheaper than Comfort or normal bronze pumps and are not brass bodies being cataphores coated. Why aren't the rest of them made this way to get the prices down? The flowswitch can be switched out and run as per a normal switched pump. That means it can be fitted as a normal secondary circulation pump switched by a pipe stat.
You make a very good point there Muggles, once the flow is started there's nothing to stop it.
Perhaps it could be wired into the light switch.
You make a very good point there Muggles, once the flow is started there's nothing to stop it.
Perhaps it could be wired into the light switch.
Or a cheap pipe stat.
I still don't see HOW a pipe stat, cheap or otherwise, will stop the pump pumping when you don't want it to.
My point is also that the loop is rather a waste of time, if you just pumped the water to the taps you'd achieve the effect of getting hot water to your taps quicker without having to faff around installing a loop then having to cure the potential problem of constant pumping. I really don't see what the loop would gain you.
Aaahhh, now I see where you're coming from with the pipe stat. Still think a decent whole house pump would achieve the effect of getting hot water to the taps more quickly without the loop though, but you seem set on doing this and nobody's going to change your mind so maybe we should just end the discussion here...
Grundfos make good quality pumps, so I have no doubt that it will be a very good pump.. I see the point that you make about reducing the quantity of water before the hot comes out as some will come from the tap and some will continue through the loop and back to the cylinder.... But what a palava!! I thought you liked to keep things simple... Hows about a bronze pump wired to the light switch of each bathroom that you have? Light on and pump runs.. By the time you have done your business, the water at the tap will be instant
When the loop is hot the pipe stat cuts out the pump.
Aaahhh, now I see where you're coming from with the pipe stat. Still think a decent whole house pump would achieve the effect of getting hot water to the taps more quickly without the loop though, but you seem set on doing this and nobody's going to change your mind so maybe we should just end the discussion here...
Except,
If you have a pump in line it will severely restrict the flow when it's off.
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local