View Full Version : tankless hot water and manabloc

07-23-2010, 10:27 AM
I have installed a 36 port manabloc with a on demand hot water supply. It is currently supplying 2 sinks a toilet and shower. The sinks work fine but the shower will not turn on the hot water unit. When I reduce the pressure on the cold side of the manablock the hot water unit comes on but the temp of the shower fluxuates and the cold supply is very low.

07-23-2010, 10:58 AM
Tankless systems require some minimum flow before they will fire. In FL, your 'cold' water could be quite warm this time of the year, and your actual hot requirements may not be large enough to trigger the unit to come on. Not sure if there's anything you can do about that other than wasting some water by adding a second or higher flow showerhead. If you adjust the shower temperature to full hot, does the tankless trigger? How cold can you get it and still have it continue to fire?