Hello All,
I have a Apollo Direct Vent Hydro Heat system that was replaced last Nov 2009. My question is in regards to I cannot keep consistent hot water to the upstairs bathroom shower(which is the only bath in the house). The HVAC repairman who installed it, came out an inspected, he says it's a 3/4" mixing valve issue and to call a plumber, which I did, the plumber inspected and was getting hot water (plenty hot) to the shower, two days later-no hot water. Can anyone help? It would be extremely appreciated.

You may just have an issue with the shower mixing valve. Has eother of your guys looked into dberis in the mixer? I would remove the shower head and soak it in CLR. I would also remove and clean the cartridge and flush the lines through a terry towel to see if I can catch and debris.

You may just have an issue with the shower mixing valve. has eother of your guys looked into dberis in the mixer?? I would remove the shower head and soak it in CLR. I would also remove and clean the cartridge and flush the lines through a terry towel to see if I can catch and debris.

My plumber said he examined the cartridge and it seemed fine, but I will try your suggestion, thanks. If that's working correctly, what would you suggest next?