Tank Replacement · Combi Boilers · GTA
Combi Boiler Installation: Get Rid of Your Tank for Good
Replace your bulky hot water tank and old boiler with one compact, wall-hung combi boiler. Heat and hot water on demand — no tank to rent, reheat or replace. Professional combi boiler installation across the GTA.
- TSSA-licensed gas work
- 20+ years in the GTA
- Old tank hauled away
Sound familiar?
Your Tank Is Costing You More Than You Think
Most GTA homes with a boiler still rely on a separate hot water tank. Here is what that really means day to day.
Cold showers by the third person
A 40–60 gallon tank only holds so much. Once it is empty, everyone waits for it to recover.
Paying rent on a tank
Rental tanks from Reliance or Enercare keep charging you every month, year after year.
Leak risk as it ages
Older tanks can corrode from the inside and leak onto your basement floor.
Wasted floor space
A tank plus a boiler takes up a corner of your basement or utility room.
Choose your unit
Combi Boilers We Install
NAVIEN Combi Boiler NFC-250/200H , 199,000 BTU Heating, 210,000 BTU Water Heating
Original price was: $180.00.$150.00Current price is: $150.00.
NAVIEN Combi Boiler NFC-250/175H , 175,000 BTU Heating, 250,000 BTU Water Heating
Original price was: $180.00.$150.00Current price is: $150.00.Tank vs. combi
One Wall-Hung Unit Replaces Two Appliances
Hot Water Tank
- Stored hot water runs out
- Heats water 24/7, even when you are away
- Separate appliance from your heating
- Takes up floor space
- Often rented with monthly fees
Combi Boiler
- Hot water heated on demand
- Only heats water when you use it
- One unit for heat and hot water
- Wall-hung — frees up floor space
- You own it — no rental fees
How the switch works
Combi Boiler Installation in 4 Simple Steps
01
Free estimate
Send us photos or book a visit. We look at your tank, boiler, piping and venting.
02
Right-sized model
We match the unit to your bathrooms and household, not the size of your old tank.
03
Clean installation
Our TSSA-licensed technicians install the combi boiler and remove the old tank.
04
Warranty & support
One year of free labour from 4Most, plus manufacturer coverage on parts and the heat exchanger.
Recommended models
Combi Boilers That Replace Your Tank
Sizing comes down to bathroom count and peak hot-water demand. These are the models we recommend most for tank replacements.
★ Most popular Rinnai
Rinnai IP120199C
- 120,000 BTU/h heating
- 199,000 BTU/h hot water
- 3+ bathrooms or radiant heat
- Homes up to ~3,000 sq ft
★ Most popular Navien
Navien NCB-240/110H
- 110,000 BTU/h heating
- 199,000 BTU/h hot water
- 2–3 bathrooms
- Homes up to ~2,500 sq ft
Still renting your hot water tank?
If you pay Reliance or Enercare every month for a rented tank, we coordinate the return and install a combi boiler you actually own.
Questions About Replacing Your Tank
Straight answers about replacing your tank water heater.
Will I really never run out of hot water?
A combi boiler heats water continuously, so it won't run out the way a tank does. It does have a limit on how many fixtures it can supply at the same moment, which is why we size it to your peak use — for example, two showers plus the kitchen tap.
What size do I need with two or three showers and a few people at home?
We size it to your bathroom count and household. Our most popular unit, the 90,000 BTU/h heating / 199,000 BTU/h hot water Rinnai, runs two showers and the kitchen at the same time.
Can one unit really replace my water heater and my heating?
Yes. It's wall-hung, so it can take the place of your existing tank or wall-mounted water heater and handle the heat and the hot water together.
I rent my tank from Reliance or Enercare. Can I switch to my own unit?
Yes. If your rental contract is up, or the rented unit has stopped working and you don't want to sign a new contract, we coordinate the return and the contract termination, then install a combi boiler you own. It's a good replacement for Baxi, Flowmax, and older Rinnai and Navien models.
What maintenance does a combi boiler need?
Very little. These units are solid and usually last 15 to 20 years, and they hardly need major service before the 15-year mark. A yearly clean and tune-up is ideal, and our maintenance plans start from $12.99. Without a plan, have a certified technician check the unit at least every 5 years.
How does the warranty work?
4Most gives you one year of free labour on any installation issue or repair. Most boiler manufacturers cover parts for 5 years and the heat exchanger, the most expensive part, for 15 years. After the first year, if you need service, you pay for the service call and the repair labour, but not for the part. We also offer extended labour warranties for 5 or 10 years.
Why isn't the installation price on the page?
Every home is different. The price depends on how the new unit will be vented, how much piping needs to change, and where your old tank and boiler are located, so we quote each home individually.
Request a Free Boiler Estimate
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