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How long does a heat pump take to warm water?

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Hi, I would like to know how long a heat pump takes to warm my geyser water? 
 

also, should I leave the heat pump on 24/7? 

Can I switch it on and off at my db box? 

Not easy to say how long it will take to heat your geyser, there's many variables involved including the size of the heat pump, the ambient operating temp, size of the geyser, how much water is being run from the geyser, how well thermally insulated it is...to name a few.

 

The best way would be a real life test where you run the heat pump for an hour and measure the temp increase. Then do the same test for a second hour.

 

You can leave the heat pump switched on permanently, it should have controls that turn it on and off and possibly even modulate its output via an internal inverter.

2 hours ago, Yash said:

Hi, I would like to know how long a heat pump takes to warm my geyser water? 
 

also, should I leave the heat pump on 24/7? 

Can I switch it on and off at my db box? 

When sized correctly it can take less time than a 3kw element on a 150L geyser for a 4.7kw(1.3kw power used) in summer and double the time during very cold winter nights if installed within 5m from the geyser. Over 5m you get too much heat loss.

The above is based on my ITS with loading valve. I have it for 9 years.

My 5.4kw ITS currently runs for about 45 mins at 12h30 afternoon to heat to the set temp of 57. In the evening it runs a further 2 cycles. One at 30 mins, the other at 40 mins.

In summer.. for all 3 runs.. it runs at a max of 1h30 odd mins. 

Mine runs in a timer. Basically between 12h30 and 20h30. And it does those 3 cycles. The 2 evening cycles is the family bath or shower routines.

A note on switching off at the db. My installer said that the machines are quite reliable and hardy.. but they dislike 2 things (based on the warranty repairs he has seen). First is kn and off switching.. like loadshedding and db switching. It messes with the computer.

Second is water outages. The pump apparently does not like that.

So i guess i would be hesitant to just switch it off at the db. Mine is on essential loads.. but i find the timer options quite flexible. So you could program a few timer slots and let it do its thing

Edited by GTP

1 hour ago, GTP said:

My 5.4kw ITS currently runs for about 45 mins at 12h30 afternoon to heat to the set temp of 57. In the evening it runs a further 2 cycles. One at 30 mins, the other at 40 mins.

In summer.. for all 3 runs.. it runs at a max of 1h30 odd mins. 

Mine runs in a timer. Basically between 12h30 and 20h30. And it does those 3 cycles. The 2 evening cycles is the family bath or shower routines.

A note on switching off at the db. My installer said that the machines are quite reliable and hardy.. but they dislike 2 things (based on the warranty repairs he has seen). First is kn and off switching.. like loadshedding and db switching. It messes with the computer.

Second is water outages. The pump apparently does not like that.

So i guess i would be hesitant to just switch it off at the db. Mine is on essential loads.. but i find the timer options quite flexible. So you could program a few timer slots and let it do its thing

After 9 happy years with an inverter start heat pump (ITS) that I switch off the power at least 2 times a day and all the LS I have no problems. I wonder how correct is the information switching off at the DB is bad. Surely with all the LS very few heat pumps should be running by now.

Just to add don't expect 40min run time if you ran a bath. Not even an 3kw element will re-heat in this time.

Edited by Scorp007

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