Another item off the list – thermal mixing valve!

In an effort to complete all the items on the list the building inspector provided, to get our final occupancy certificate, yesterday I spent what ended up being far too long installing a thermal mixing valve on our domestic hot water tank.

As part of new building code requirements, hot water heaters need to have a thermal mixing valve installed to prevent scalds at any hot water faucets in the house.  Our shower valve already came with one of these built-in, but to comply with Ontario Building code you need one installed at the hot water heater.  A hot water heater is typically set at 140F, to prevent legionella bacteria (cause of legionnaires’ disease), but 140F is a scald hazard. To prevent scalds, you install a thermal mixing valve – which mixes some cold water with the hot water coming out of the hot water heater, to regulate the temperature of the hot water to something more reasonable.  I chose around 118F-120F, which is about the maximum it should be set to.

Thermal Mixing Valve installed
Thermal Mixing Valve installed

Getting the mixing valve installed was quite the comedy of errors.  To install the valve, I had to remove that black connector (labeled HOT/CHAUD) section of the exhaust/flue system, so that I was able to screw on the cold and hot water portions of the mixing valve.  Getting that off was a little tricky, and then once I got it off, I accidentally knocked my small flashlight down into the resulting hole, and it ended up at the bottom of the hot water heater on top of the gas heating element.  *sigh*  That one careless mistake meant I now had to remove the gas heating element, to retrieve the flashlight.  You might think that might be fairly straightforward, which it was, but it was finicky, and an incredibly frustrating task getting it done.

Thankfully, that is all behind us now, the mixing valve is installed and working, leak-free, so that is one more thing we can cross off the list.  I am hoping to get back outside today and get more of the siding finished, so we can have it wrapped up before it’s truly miserable to work outside.  Will post more soon!

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