Triangle Tube Indirect Water Heater Repair Long Island

Indirect Water Heater Brand

About Triangle Tube Indirect Water Heaters

When it does fail, you'll want a replacement that fits your boiler and piping. We repair and service Triangle Tube indirect water heaters across Long Island, Nassau and Suffolk Counties, stock the common parts, and install new indirect tanks when it's time. Domino Fuel is family-owned since 1981, with 24/7 emergency service.

Triangle Tube dates to 1946 and worked out of West Deptford, New Jersey. It was part of Groupe Atlantic, the French heating company that also owns Ideal Boilers. Triangle Tube said it was the first to bring the fire tube heat exchanger to the residential market.

On November 3, 2025, Triangle Tube ceased operations. Open equipment orders were cancelled, and anything bought from that date on carries no warranty. Spare parts are still sold through stocking distributors as long as they last.

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All Models Serviced

Model Lineup

Triangle Tube Indirect Water Heater Models We Service

Two lines are still out there in Long Island basements. The Smart 316 is tank-in-tank: your drinking water sits in an inner stainless tank, and boiler water fills the shell around it. The Cardinal is coil-in-tank, with boiler water running through a corrugated stainless coil.

Smart ratings below assume 200 degree boiler water and a 90 degree rise. The Cardinal row is rated at 180 degree boiler water and 14 GPM.

Model	Domestic Capacity	First Hour Recovery	Boiler Output
Smart 30	28 gal	140 gal	87,000 BTU/hr
Smart 40	36 gal	180 gal	112,000 BTU/hr
Smart 50	46 gal	220 gal	140,000 BTU/hr
Smart 60	56 gal	410 gal	270,000 BTU/hr
Smart 80	70 gal	460 gal	300,000 BTU/hr
Smart 120	119 gal	650 gal	420,000 BTU/hr
Cardinal 40	40.6 gal	228 gal	122,000 BTU/hr

Good to Know

How a Triangle Tube Indirect Works With Your Oil or Gas Boiler

When the tank's thermostat calls, the boiler sends hot water into the Smart's outer shell or the Cardinal's coil. That heat passes through stainless steel into your domestic water. On a Smart tank, the boiler side runs at low pressure, with a 30 psig maximum and about 12 psig typical.

Triangle Tube's manual says to set the boiler limit at least 20 degrees above the tank thermostat and never above 210. It shows both priority and non-priority piping, so the tank can pair with an oil boiler or a gas boiler. The boiler side has to be a closed loop with oxygen-barrier tubing.

Long Island Homes

Triangle Tube Indirect Water Heaters for Long Island Homes

Water quality is the big one. Triangle Tube's limits call for chloride under 150 ppm and pH between 6 and 8 on both the boiler and domestic sides. Long Island wells and softened water can drift out of range, so a test is cheap insurance.

Since new Triangle Tube tanks aren't coming, plan ahead if yours is getting old. A tank that fails in January means a cold week if no replacement is lined up. We can measure your space and boiler now and have a plan ready.

Warranty

Triangle Tube Indirect Water Heater Warranty

Triangle Tube required owners to register a tank within 60 days of installation for warranty coverage. After the shutdown, it set a September 30, 2026 deadline to file warranty claims. Purchases on or after November 3, 2025 carry no warranty.

In practice, plan on paying for repairs and replacement yourself. Check your paperwork and the claims notice on Triangle Tube's site if you have questions about an old claim.

On top of the manufacturer's coverage, Domino backs every installation with a 1-year labor warranty.

Compare Brands

Triangle Tube Smart vs Lochinvar Squire

When a Smart tank fails, the Lochinvar Squire is a natural replacement. Both use 316L stainless steel, but the Squire is coil-in-tank instead of tank-in-tank. Lochinvar is owned by A. O. Smith and still builds the Squire, with a limited lifetime tank warranty for single-family homes.

The swap usually means re-piping the boiler connections and resizing the circulator, since the Squire needs 14 GPM through its coil. See our page on Lochinvar indirect water heaters for sizes.

Repair & Service

Triangle Tube Indirect Water Heater Repair and Service

These are the Smart and Cardinal problems we fix most often.

Lukewarm water: the tank thermostat has drifted or the boiler limit isn't 20 degrees above it.
Gurgling or air in the boiler side: the air vent on top of the tank needs bleeding or replacing.
Boiler pressure climbing: a sign the inner tank may be leaking into the boiler water; call us right away.
T and P valve keeps releasing: shut the cold inlet and call; it can mean excess pressure or a failed valve.
No hot water, heat works: failed zone valve, circulator or priority relay.
Water on the floor: a leaking fitting or a failed tank.

Good to Know

Triangle Tube Indirect Tune-Up and Parts

We stock the common parts, including thermostats, air vents, T and P valves, mixing valves, circulators and zone valves. Triangle Tube parts like drywell kits are getting harder to find, and we'll tell you up front when a fix isn't worth it. A yearly tune-up checks the air vent, system pressure, mixing valve and every fitting. We pair it with boiler service.

Good to Know

Triangle Tube Indirect Water Heater Replacement

Price depends on the new tank's brand and size, piping changes, controls and code items. Call for a quote.

We check the old tank, your boiler's output and your hot water use.
We recommend a current indirect that fits the space and the boiler.
We drain and remove the Triangle Tube tank, then re-pipe the boiler coil connections.
We install the new tank with a relief valve, expansion tank and mixing valve.
We set the controls, fire the boiler and test a full heat-up.

FAQ

Triangle Tube Indirect Water Heater Repair and Replacement on Long Island FAQs

Common questions about this indirect water heater brand on Long Island.

1Is Triangle Tube still in business?

No. Triangle Tube ceased operations on November 3, 2025. Spare parts are sold through stocking distributors while they last.

2Can my Triangle Tube Smart tank still be repaired?

Usually, yes. Thermostats, air vents, valves and circulators are standard repairs. A leaking inner tank can't be fixed, and the tank has to be replaced.

3Is my Triangle Tube indirect still under warranty?

Probably not. Triangle Tube set a September 30, 2026 deadline for warranty claims, and purchases after November 3, 2025 carry no warranty.

4What should replace a Triangle Tube indirect?

Another indirect sized to your boiler. A Lochinvar Squire stainless tank is a common choice, and we'll compare options with you.

5Why is my boiler pressure rising with a Smart tank?

It can mean domestic water is leaking from the inner tank into the boiler side. Call for service soon, since the boiler relief valve may start to discharge.

Triangle Tube Indirect Water Heater Repair and Replacement on Long Island

About Triangle Tube Indirect Water Heaters

Triangle Tube Indirect Water Heater Models We Service

How a Triangle Tube Indirect Works With Your Oil or Gas Boiler

Triangle Tube Indirect Water Heaters for Long Island Homes

Triangle Tube Indirect Water Heater Warranty

Triangle Tube Smart vs Lochinvar Squire

Triangle Tube Indirect Water Heater Repair and Service

Triangle Tube Indirect Tune-Up and Parts

Triangle Tube Indirect Water Heater Replacement

Other Reliable Indirect Water Heater Brands We Offer

Triangle Tube Indirect Water Heater Repair and Replacement on Long Island FAQs

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