Hot water system, tank / secondary return query

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Hi,

Is it right that when the secondary return pump is off, when you run hot water, it runs from the tank, and without the secondary return pump, when the tank hot water is finished you just get cold water? i.e the incoming water won't run through the boiler to heat it back up?

Some of the pipes for the secondary return run next to the skirting, in the heat wave it makes the rooms really hot/ had the bright idea of switching off the secondary return pump thinking the system would work but just take longer for the hot water to run through.

What I found instead is that it seems when the hot water is all out from the tank, any draw off stays cold. i see the plumbing and the incoming water Ts off one to the boiler one to the tank.

Does this mean we have to keep the secondary return pump on then to keep the Tank Water hot? the normal pump setting is a 4 hours in the morning and 5 in the evening. Thinking I need to get the exposed pipes boxed in?
 
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If you have no insulation on hot water output from HWC and seconary return all the exposed pipework is bound to act as a radiator.
What I have is a thermostat on the return so the pump turns on and off.
IMO a SR is bonkers not controlled properly and uninsulated unless you have money to burn.
 
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Is it right that when the secondary return pump is off, when you run hot water, it runs from the tank, and without the secondary return pump, when the tank hot water is finished you just get cold water? i.e the incoming water won't run through the boiler to heat it back up?

That's not what a secondary return on the HW cylinder does. The HW you get at the tap is separate to the HW from the boiler that heats the water in the cylinder up. The SR pump doesn't channel the HW through the boiler.

In larger properties, the pumped return circulates HW around the HW distribution pipework to ensure that you have almost instant HW at the taps. If that pipework isn't insulated then you are using the HW to heat the space around the pipework (as you have seen) which is a huge waste of energy. In that type of system the pipework should be very well insulated otherwise the HW from the cylinder will eventually cool down.

Can you post a pic of the pump you are looking at?
 

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