Frozen water pipe - inside, not outside

[Cougarkid]

Well, this was a bit different.

We have had cold nights (down to 8 degrees) before this season with no issues. My water line has heat tape run along it's length encased in foam pipe insulation. Dump bay (drivers side) is heated by furnace. Holding tank area is heated by ambient heat from flexible furnace duct.

Water heater above dump bay (drivers side), back side under the bathroom sink cabinet (inside). Toilet in on the same side of rv. Shower and kitchen are on the passenger side. Water lines to run across rv in tank bay for the shower and kitchen.

Had a cold night Friday, down to 12 degrees. Got up Saturday morning and had a strange water issue:

Hot/cold water worked at the bathroom sink and toilet.
Hot water at shower and kitchen.
NO cold water at the shower and kitchen.

Opened the cold water at the shower and after about 10 minutes it started running. Back to cold water everywhere again.

Strange that the cold water pipe "froze" inside the enclosed, insulated bay.

I plan to look at the pipe runs and location of the heat duct to the pipes. Will move duct close to the piping to help keep them warm. Could add a vent in the run (flexible) IN the bay to add heat, too.

Mike

[wa8yxm]

The pipes in many motor homes run along the outside wall ABOVE the floor (That is the ones running long ways, the ones running across the motor home usually are in the wet bay down below) Since they are running along outside walls, if they run UNDER a slide (As mine do) that area is not well heated by the inside heat, plus there is the chance (likely hood in fact) of an air leak adding to the freezing. I have to pull the bottom drawers in my wardrobe to prevent freezing of those lines.

[Cougarkid]

Since the shower had no cold water and it is the 1st faucetabove floor after the pipes run across the rv, I believe the pipe froze in the bay, under the floor.

No issues since, but I still need to get under there and do something.