When I went to take a shower today all I got was a trickle of hot water from the spigot. Figured the pipes were frozen; they're near a north wall in a leaky old house. The hair dryer took care of the water pipes. But my tub isn't draining. Could the p-trap for its drain be frozen? I vacuumed the water out of the tub and drain. I spent about an hour shooting hot air into the drain with a hair dryer. No luck. Gingerly tried boiling water. No luck. Opened the overflow and tried shooting hot air down it. No luck. Can't access the drain pipe from the floor below. Drilled two holes in the ceiling and found what might be a very thick old subfloor above it -- century home. Any suggestions? Thanks.

 

The trap is not right under the drain and so the hair dryer is probably ineffective. If the hot water were frozen, the "trickle" would quickly increase to full flow just by keeping the water running. I would expect the trap to be farther away from the wall than the supply piping, and it is 3 times bigger in diameter, so I suspect that it is not frozen.
Have you experienced frozen pipes in this tub/shower before?
Did you completely pull the drain stopper out?
If you are sure that the drain is frozen, I would suggest using tubing and a drill pump to pump warm salt water down the overflow pipe.

 

The stopper is out. I moved here only in May and so do not know if the drain froze before. A plumber who I reached on the phone but was too busy to come out speculated that there's an air leak in the wall that's hitting the pipe. The tub is on the north wall of the house and we had a strong very cold north wind the other night.

I'll try warm salt water. Also thought about using windshield wash rated for -40.

 

Fixitron, thanks for suggesting warm salt water. The drain's now running and I think that's what did the trick. I mixed hot water with safety salt and poured in about a cup and a half. Also used a space heater to really warm up the area.

As a preventive, I'm going to keep a jug of -40 windshield wash in the bathroom and pour a cup or so down the drain after using the tub or shower.

Thanks again.

 

Glad you got the problem solved. Hope you are not creating another one. Pouring hazardous chemicals down the drain is illegal in most areas. I would read the label on the anti-freeze for info on the chemical content. If you are on a septic, it is probably not good for it either. Check for any EPA warnings on the bottle of anti-freeze. Good luck.

 

Good point Dragon. The label says it contains methyl alcohol and warns against swallowing it. Probably not a good idea to put it down the drain. I'm on a sewer system, not septic.

I have to find some kind of preventive. Our January/February temperatures go well below those on Monday night and stay there. Finding and filling the air leak would require removing the tub. It's one of those 3-piece (tub/wall/ceiling) fibreglass/acrylic kits that fit into an alcove. Removing it is beyond me, let alone putting it back. Plumbers here are so busy they don't even answer their phones or return calls.

If I recall correctly, there's a septic-safe anti-freeze that people use when winterizing cottages. If it's septic-safe, seems to me it should be OK for the sewer system. Alternatively, I wonder if:

1. A cup or so of safety salt mixed with water would work. The drain pipe is ABS. The salt water would sit overnight till we shower in the morning. Or;

2. Don't laugh: a cup of cheap wine with the highest alcohol content I can find

Any thoughts and suggestions are more than welcome.

 

Check RV anti-freeze for waterlines. Many campers use it to winterize the whole system of their campers.

 

Got it. Called "plumbing antifreeze." It's the same stuff that cottagers use to winterize their drains. Label also says it's for swimming pool equipment.

Thanks