force higher pressure in tankless

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Mosher

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hhi my understanding is that an instant hot will not allow water through until it finishes heating , however this causes low pressure on the hot water lines which then causes cold water to backfeed into the hot line . is there any way to force the heater to let the water through even if its not fully heated
 

Bannerman

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When a hot water faucet is first opened, cold water will flow through the tankless unit to cause the unit to activate the gas burner or electric element. As tankless units do not heat water until water is actually flowing through the heater, because most tankless units do not store any amount of hot water, the initial water exiting from the tankless unit will remain cold until the burner is fired and achieves full output to instantly heat the water up to the desired temperature. As long as water continues to flow through the tankless unit, it will continue to heat the water to the desired temperature.

Some tankless units are equipped with a recirculation pump and a small buffer tank to store a small quantity of hot water to cause heated water to be instantly supplied to the hot supply lines once a hot faucet is activated.
 
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Jeff H Young

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When a hot water faucet is first opened, cold water will flow through the tankless unit to cause the unit to activate the gas burner or electric element. As tankless units do not heat water until water is actually flowing through the heater, because most tankless units do not store any amount of hot water, the initial water exiting from the tankless unit will remain cold until the burner is fired and achieves full output to instantly heat the water up to the desired temperature. As long as water continues to flow through the tankless unit, it will continue to heat the water to the desired temperature.

Some tankless units are equipped with a recirculation pump and a small buffer tank to store a small quantity of hot water to cause heated water to be instantly supplied to the hot supply lines once a hot faucet is activated.
Instahot or instant hotwater heater and tankless are differant animals. the former is /was popular for making tea, or ramen etc at your kitchen sink
 

WorthFlorida

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hhi my understanding is that an instant hot will not allow water through until it finishes heating , however this causes low pressure on the hot water lines which then causes cold water to backfeed into the hot line . is there any way to force the heater to let the water through even if its not fully heated
Look over the owners manual settings. Is your tankless just for domestic hot water or also used for heating the home. Do as Bannermann suggest as some units do have a recirculating system. At the furthest fixture a check valve is added to block cold water from entering the hot side of the faucet. It uses the cold water line as a return to the thankless. To stop the recirculating temperature is used or just a timer say every 10 minutes or more.
 

John Gayewski

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hhi my understanding is that an instant hot will not allow water through until it finishes heating , however this causes low pressure on the hot water lines which then causes cold water to backfeed into the hot line . is there any way to force the heater to let the water through even if its not fully heated
Your understanding is not correct. The question isn't a concern.
 
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