June 19, 2026 · 6 min read
Why winterizing matters here
Water expands as it freezes. Any water left sitting in your RV plumbing over a Calgary winter can freeze, expand, and crack the lines, the pump, the water heater, or the fittings in between. Those repairs are far more expensive than an afternoon of prevention.
The goal of winterizing is simple: get every drop of water out of the system and replace it with RV antifreeze so nothing left behind can freeze and do damage.
The core steps
Drain the fresh water tank, the grey tank, and the black tank. Open the low-point drain lines and let the fresh-water system empty completely.
Drain and bypass the water heater. Never put antifreeze through the water heater — bypass it first. Make sure it has cooled and lost pressure before you open the drain plug.
Pump RV antifreeze (the pink, non-toxic kind — not automotive antifreeze) through the lines until it runs from every hot and cold tap, the toilet, the shower, and the outside shower if you have one. Pour some into each drain to protect the P-traps.
Disconnect and store the battery somewhere it will not freeze, and give the unit a good clean and dry inside so you are not closing moisture in for the season.
When to bring it in
If you are not confident bypassing the water heater, or you have had leaks or soft spots before, it is worth having it winterized professionally — a missed step is what causes the spring surprise. The same trip is also a good time to catch a small water leak before the freeze makes it a big one.
At Horton RV Services in Calgary we winterize units and check for early water damage at the same time, so you are covered going into the cold months.
Common questions
When should I winterize my RV in Alberta?
Before the first hard frost — in the Calgary area that usually means having it done through October, and certainly before overnight lows sit below freezing.
Can I use regular automotive antifreeze?
No. Use only non-toxic RV antifreeze (the pink kind) in your plumbing. Automotive antifreeze is toxic and not safe for a drinking-water system.
What happens if I skip it?
Water left in the lines can freeze and crack the plumbing, pump, or water heater. You typically find out in spring when you fill the system and it leaks — turning a simple job into a much larger repair.