Tankless Water Heaters Problems And Reviews

Question: Tankless water heater not functioning properly! help?

(Posted by: TANTANTAN on 2009-11-03 09:40:18)

Ok so I have a tankless water heater I purchased a few months ago. When we shower using the tub only the water regulates perfectly but as soon as we turn the shower on it is impossible to regulate, I have to constantly shut off the water because it gets too hot or too cold. Could this be a problem with my water heater or is it something with my shower?

Posted by: wallmeis on 2009-11-03, 10:16:38

Tankless water heaters have a minimum flow requirement to trigger the heater. For example, the Rheem 74 natural gas series it is 0.66 gallons per minute. It's possible a highly eco-friendly shower head has such low flow that it doesn't solidly trigger the water heater. If this is the cause, then moderately turning on another hot water faucet somewhere will result in consistent hot water. If that proves out, then the long term solution is to upgrade to a higher flow shower head. Another possibility is the washers in the shower control valves are loose and flopping around. Take them out and have a look. It is necessary to shut off the dwelling's water supply to do this.

Posted by: Ralph Z on 2009-11-03, 18:42:43

Truth is: You cannot have low flow shower heads and expect water temp to be normal.