Hi, just had a twin coil Tribune 250 l unvented cylinder fitted, with a view to fitting solar panels sometine in the future. Would it be worth in the meantime connecting the two coils in parallel to the boiler ?
twin coil cylinder in parallel
- Thread starter stahlfresser
- Start date
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Not really worth the effort imho.
thks ht, forgot to mention that the plumber , plumbed in the bottom coil to the boiler by mistake, would it be worth in this case getting it plumbed in parallel, getting it swapped to the top coil or leaving it as it is ? paul
Hi,
Leave it in the bottom until the solar is fitted and change it about then.
Leave it in the bottom until the solar is fitted and change it about then.
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thanks, will leave as is and not plumb parallel
B
BigBurner
Connect it in series. Return of the boiler to the bottom connection of the bottom coil. Top of bottom coil to bottom of top. Top of top to the flow of the boiler. If you have a condensing boiler it will make a difference.
thanks bb, will give it ago paul
different boroughs have different thought on which way to go .. sheffield go flow to the top....
mansfield go flow to the bottom..
general thought is flow to the top ... but i see sense in both ways to be honest.
but i go flow top as i was taught that way.
mansfield go flow to the bottom..
general thought is flow to the top ... but i see sense in both ways to be honest.
but i go flow top as i was taught that way.
Cast iron rads have been plumbed flow top , return bottom , so would seem to make sense to plumb boiler same
The Kingspan cylinders(Range, Albion,Ultrasteel,WB) are all coil in coil, the primary's are at the same level and either can be used for the flow or return.
there used to be different heats calcs for radiators with bottom opposite entry and top/bottom entry.
a lot of councils ask for top/bottom opposite entry for elderly for ease of control and also added output. can be noisier though ./
never figured out why though .
a lot of councils ask for top/bottom opposite entry for elderly for ease of control and also added output.
can be noisier though ./ never figured out why though .
B
BigBurner
Best have the flow on the outer coil as it is larger and has more water around it.
Always have the flow connected to the top of a cylinder coil. Coils are far larger than before and especially when using a large quick recovery coil. As water is being drawn off, it will give hotter secondary water making the cylinder effectively larger.
Using a quick recovery coil means you can downsize a cylinder, but the top coil connection must be connected to the boiler's flow.
For best cylinder recovery using a very small cylinder, use a plate heat exchanger, probe cylinder stat and bronze pump on a direct cylinder. A 60 litre cylinder and 30kW boiler will do two bathrooms, although it may struggle filling two at once. The equiv performance on a Part L coil would mean a far, far larger cylinder, and more expensive overall too.
In the olden dayes when coils were very small, connecting the boiler flow to the coils bottom connection meant a few extra inches of cylinder was heated at the bottom.
Oddly enough that still applies nowadays!
Connecting the flow to the lower connection will slightly increase the power input and speed the reheat. But its less efficient with a condensing boiler.
So unless special circumstances apply always fit the flow to the top of the coil but be aware that some existing systems may be the other way round.
Tony
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