I live in a manufactured home and I want to add a whole house water filter to the water inlet. The water inlet is under neath the house and is accessible. I am able to shut off the main water and all connections at sinks, toilets, washing machine and refrigerator. However, the hot water tank does NOT have a shut off on the cold water inlet. The hot water heater is higher than where I will be adding the filter.
If I open the pipe under the house will the water from the hot water tank drain out?
I'm thinking yes, but I really need to know for sure, BEFORE I actually make the cut.

Thanks,
John

There might be a little water that leaks out, but if the hot faucets are kept closed, a vacuum can be formed, preventing a flood of water. There also should be an anti-siphon hole in the inlet tube of the heater, limiting how much water can siphon out.

while the water is off, add a shutoff to the water heater

Well, finally got around to plumbing the filter in. Piece of cake! There was very little water coming back and the hot water heater DID NOT drain. If it had, I was prepared to add a cold inlet shut-off. The reason I did not, is that the inlet is on the bottom and I would have had to drain the tank in order to add the shut-off valve. If the water heater needs to be replaced, I will add it then.

I'll also add that there is NO reduction in water pressure. Just chlorine free water!

Thanks for the help.

John



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