What the job involves
Shut off and drain
Turn off the water and the power or gas, attach a hose to the drain valve, and drain the tank.
Disconnect the old unit
Disconnect the supply lines, gas or electric connection, and the venting, then move the old tank out.
Set the new tank
Position the unit on a level base or in a drain pan and connect the supply lines with new flex connectors.
Connect fuel and vent
Reconnect gas or electric, install the vent, and check for proper draft.
Fill, test, and relieve
Fill the tank with a hot tap open, check for leaks, then restore power or gas and confirm the temperature.
The hard parts
Weight and access
A full tank weighs hundreds of pounds, and an empty one is awkward on stairs.
Gas and venting
A bad gas connection or poor draft can leak gas or carbon monoxide.
Soldering or crimping
Copper connections need soldered joints, while PEX needs the right tools.
Code items
Expansion tanks, relief piping, and drain pans have rules.
Not comfortable with gas or soldering?
Call. A plumber can do the swap and test the venting.
DIY or hire a plumber
DIY is realistic when
- You are swapping like for like, electric to electric
- You are comfortable with plumbing connections
- You can move the tank safely
Hire a plumber when
- The unit is gas or needs new venting
- You are changing fuel or size
- You are unsure about permit and code items
A planned install is covered on the water heater installation page, and a failed tank in winter is handled quickly through water heater replacement.
Safety points that matter most
- Never work on a gas unit with the gas on.
- Use a leak detection solution on every gas joint.
- Check that the vent draws by holding a match near the draft hood after the burner starts, or ask a professional to test it.
- Install the relief valve with a full-size discharge pipe that ends near the floor.
- Do not turn on the burner or elements until the tank is full of water.
The last point is the most common mistake. An electric element energized in an empty tank burns out in seconds. A gas burner on an empty tank can damage the tank bottom.
Time and effort for a first-timer
Plan on most of a day. Draining a full tank through a garden hose takes a while, and the old unit has to go up or down stairs. Have a helper for lifting. If something goes wrong halfway through, you are without hot water until it is fixed, so start early in the day and have a plumber's number ready.
When the job is harder than it looks
Several things turn a simple swap into a long day. A corroded gas line, stuck shutoff valves, a vent that no longer meets code, or fittings that break when you move them all add work. Older homes in Forest Lake are more likely to have these surprises than newer ones.
If the shutoff valves will not close fully, stop and call. Forcing a stuck valve can snap it and flood the utility room, and that is a worse problem than the one you started with.
Minnesota owner rules and Forest Lake permits
Minnesota Statutes section 326B.46 says an individual without a contractor license may do plumbing work on their own residence if the work complies with the state minimum standards and no local ordinance forbids it. The statute excerpt does not address permits or inspections, so ask the Forest Lake building department what applies before you start.
Contractors must be licensed, and the state Department of Labor and Industry offers a lookup to check any plumber. Gas appliance work involves safety rules, so ask the gas utility or a licensed professional if you are unsure. For homes in Wyoming or Hugo, check with your own city.
Questions Forest Lake Homeowners Ask
Minnesota allows an owner to do plumbing work on their own residence if it meets state minimum standards and no local ordinance forbids it. Ask the Forest Lake building department about permits.
A plumber typically needs a few hours. A first-time DIYer should allow most of a day.
Yes. Gas connections and venting add risk and need careful testing.
Wrenches, a hose, pipe tools for your pipe type, a dolly, and the new fittings and flex lines.
Often. Ask the Forest Lake building department.
Turning on the power or gas before the tank is full. Fill the tank and open a hot tap until water flows before energizing it.
Sources
- Minnesota Statutes section 326B.46 (state statute)
- Minnesota Department of Labor and Industry plumbing contractor licensing (state agency page)