Water pushing out of city water connection.

[Stump Jumper]

I was recently winterizing my motorhome by putting some RV antifreeze in the water holding tank and pumping it through the lines using the RV water pump. I noticed that it was pushing some antifreeze out of the city water hookup. I have used the holding tank water before and never had this problem. I assume the system uses a backflow prevention valve. When I was winterizing, the pump was pulling some air as well as the antifreeze, could this be the problem?

[whem2fish]

there is a oneway check valve in the connector for city water could be trash, bees nest or something may try blowing a small amount of air to dislodge foriegn matter
dave

[DriVer]

Filling a holding tank to winterize an RV is a waste or resources and is a bigger problem when you need to get rid of the anti freeze in the tanks in the spring.

One should rather seek to install a winterizing kit where RV anti freeze can be drawn directly into the water system bypassing the water heater and the fresh water tank.

The least (BEST) expensive option would be to get a blow out plug and use a compressor and blow out all the water. This can work for all the installed devices in your RV including ice makers, toilets, dishwasher and washing machines. Dump 4-6 ounces in each trap and you can winterize most any RV with less than a gallon of RV anti freeze.

[skigramp]

As far as winterizing traps and flush valves ... windshield washer fluid works great ... it is easier to clean up spillls ... and where I live is about half the cost of RV antifreeze ...

DO NOT put windshield washer fluid in your fresh water system