Hot water does not flow in shower when temperature is below -10 celsius
I installed a shower stall last fall in the basement with everything going well. Winter came and now having problems with hot water not coming down the pipe when temperature plummets below -10 Celsius. I noticed that as the day the temperature goes up the hot water comes down, as the temperature plummets the, hot water stops. Note that the cold water has no issues at all.
Note that to install the shower stall I modified the hot and cold water lines that come to the cloth washer to take a branch to the shower. I installed 2 shut off valves (one for hot and one for cold water pipes) on each of the branches, in addition to the shut off valves on the clothes washer, so that to enable me to shut off the water when servicing the shower stall without having to shut off the main water line.
The issue is not with the shower faucet. I verified that by shutting off the valves on the shower and verifying whether the water comes down to the clothes washer... the cold water does but not the hot water. So now when this happens I cannot even use the washer.
I read about water air block being one of the possible causes. So I did test for that by running a hose from the cold water to the hot water pipes at the clothes washer shut off valves. I turned on the shut off valves and both the cold and hot lines (which is now cold) work at the shower. This means that if there is any air blocks that would have cleared it... that did not work.
I would appreciate any help on this.
Thanks,
Sharbin