Hot water recirculation instant hot water systems clarified

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Hot water recirculation systems tend to be referred to by many different names, all meaning pretty much the same thing. Circulation pumps, and recirc pumps, recirculation pumps, recirculating pumps are all the same thing.

Hot water recirculation systems tend to be referred to by many different names, all meaning pretty much the same thing. Circulation pumps, and recirc pumps, recirculation pumps, recirculating pumps are all the same thing.

They refer to the practice of circulating hot water through your plumbing in order to have rapid hot water and don waste water running it down the drain while you're waiting. Much like most good things there are trade offs.

First, let's analyze a recirculation system that is basic and get comfortable with how it works. The system consists of the water heater, a pump, and a loop of pipe coming from the exit of the water heater, going from sink to sink in a looped way, and returning from the last sink back to the pump which has its wall socket connected to either the inlet to the water heater or to the drain valve.

Recirc pumps

Often called recirc pumps, as well as recirculation pumps etc. the hot water circulating pumps are designed to slowly circulate the hot water through the piping at a low velocity. There's no requirement for flow that is high since a fine flow that is low however keeps the water piping hot through the whole system. High flow rates run constantly may also lead to conduit erosion and eventually require replacement of the pipes.

Instant Hot Water

Such a system will provide you with almost instantaneous hot water, as you are able to see. This can save tremendous amounts of water while you waited for the hot water to arrive at the fixture that would have already been run down the drain. The fee you pay is in the cost of the energy used up keeping your radiator system that is giant hot.

The water heater needs to fire up more frequently and for longer to keep the temperature as the heat energy is let loose on the environment from dropping.

You can minimize your energy prices by placing the pump on a timer to ensure that it only runs when there are people around that might want to use hot water. Leave it during the day and away late at night if no one is home during the day. Your losses can easily cut in half in most cases although it still wastes a lot of energy.

The downside is of course, if you'd like hot water when the pump isn't running you will have a lengthy wait. In case you don't have a length wait you likely did not want a hot water recirculation system to begin with.

Another way to control the traditional hot water recirculation systems is with temperature control. Have the pump turn on when the temperature drops to some preset value, like 100 degrees, and when the temperature reaches 120 degrees turn away the pump. The temperature detector is called an aquastat, and generally clamps onto the hot water pipe near the pump.

Since you are still squandering lots of energy since you have filled with hot water.

If you do have a hot water recirculation system you should insulate all to minimize heat loss.

Tankless Water Heaters

Tankless water heaters usually don't function with hot water circulating systems since for one thing hot water pumps do not produce enough flow. Tankless Water usually need at least 1/2 gallon per minute to operate.

Hot water recirc systems additionally cause the water heater to cycle on and off often since there is no tank. With many brands of tankless water heaters the guarantee will be voided by a hot water circ system.

Tankless water heaters take longer to provide hot water than tank type water heaters and so it is not too good hot water recirculation systems don't work with them.

Well that's about it for hot water recirculation systems, some hot water piping, a water heater, a pump and several faucets. Do not forget the pipe insulation.