THERMO 2000 BuffMax BUFF30-1.5NPT-HRZ-HC Buffer Tank (30 gallons)
Thermo 2000 BuffMax 30 US gallon buffer tank and hydraulic separator, with four 1 1/2 in NPT side connections, for heating or chilled water.
Model numberBUFF30-1.5NPT-HRZ-HC
514 316-2973 · sales@airgreen.ca
Quick facts
Each zone at its own pace, without running the boiler ragged
A hot-water heating system with several zones has a weak spot: the zones open and close at different times, and the heat source has to keep up. The Thermo 2000 BuffMax BUFF30-1.5NPT-HRZ-HC buffer tank handles this in a single 30 US gallon vessel. The manufacturer presents it as a 3-in-1: buffer tank, storage tank and hydraulic separator.
The role of a hydraulic separator in a multi-zone house
The BUFF30 has four 1 1/2 in NPT side connections, two on each side. On one side, the electric boiler or air-to-water heat pump circulates its water through the tank. On the other, the zone circulators draw the water they need. The two circuits no longer interfere: a zone that closes does not change the flow through the source, and the source does not impose its pressure on the zones.
Picture a house in Laval with a radiant floor in the basement, another in the kitchen and bathrooms each controlled by their own thermostat. Or a duplex on the South Shore where each unit has its own zone. In both cases, heat calls are small and staggered. The tank’s 30 US gallons give the source enough water to run longer cycles. Thermo 2000 recommends the BuffMax precisely for multi-zone systems, low-mass boilers and heat pump systems.
Dimensions and connection in the mechanical room
The tank is 62 1/2 inches high and 18 inches in diameter. It stands on adjustable legs and comes with a 1/2 in ball valve, a 1/2 in automatic air vent, a 2 1/2 in temperature and pressure indicator, an immersion well and a 3/4 in drain valve. Three additional 1/2 in connections let us place the temperature sensor at the height that suits your source’s control.
The 2-inch HFC-free polyurethane insulation limits heat loss to 1/2 °F per hour, according to Thermo 2000. The tank accepts up to 150 psi and 121 °C (250 °F). Thanks to the HC code, it takes heating water as well as chilled water. One rule never changes: it works in a closed loop and must not be connected to domestic hot water or to an atmospheric system.
Our installation, step by step
- Free on-site visit and estimate, anywhere in Montreal, Longueuil and the North Shore: we note the source, the zones and the space available.
- A written quote that states the size chosen and the work planned.
- Setting the tank, connecting the source side and the zone side, placing the sensor in the immersion well.
- Filling, purging the air and commissioning, with a check of each zone.
AirGreen is a family business established in Montreal for more than 15 years. We hold RBQ licence 5645-9605-01 in ventilation, refrigeration and electrical work. Thermo 2000 warrants the tank for 5 years and the mechanical parts for 2 years, under its terms.
Bring order to your zones
Describe your system, the number of zones and the heat source: we will tell you whether the BUFF30 fits. The estimate is free, and financing is available.
A hydraulic separator and a water reserve for a multi-zone system
In a house where several hot-water heating zones open and close at their own pace, the BUFF30 separates the electric boiler or air-to-water heat pump circuit from the zone circuit, while keeping 30 US gallons of water ready to distribute.
- Radiant floor split into several zones, each with its own thermostat
- Duplex or triplex where each unit has its own hot-water zone
- Air-to-water heat pump paired with zone circulators
- Replacing a hydraulic separator and a small tank with a single vessel
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Closed loop only: no connection to domestic hot water or to an atmospheric system, according to Thermo 2000.
- Plan for 62 1/2 in of height and an 18 in diameter, plus clearance for the piping on both sides.
- The tank does not replace the circulators: the source and the zones each keep their own pump.
- Maximum temperature of 121 °C (250 °F) and maximum working pressure of 150 psi.
- 1/2 in ball valve
- 1/2 in automatic air vent
- 2 1/2 in temperature and pressure indicator
- Immersion well
- 3/4 in drain valve
- Adjustable legs
Manufacturer documents
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Frequently asked questions
What does hydraulic separation bring to a multi-zone system?
The boiler circulator and the zone circulators no longer push against each other. The source circulates its water on one side of the tank, and the zones draw theirs from the other side, at their own flow rate.
Where does the boiler or heat pump sensor go?
In the supplied immersion well. The tank also has 3 x 1/2 in well connections: we choose the position based on how your source’s control reads the temperature.
How much space do I need?
The tank is 62 1/2 in high and 18 in in diameter. Add clearance for the connections on each side and access to the 3/4 in drain valve.
Can it be used in summer with chilled water?
Yes. The HC code means this tank accepts heating water and chilled water, if your source produces chilled water.
How does the warranty work?
Thermo 2000 covers the tank for 5 years and the mechanical parts for 2 years, in Canada and the United States. Under its terms, removal, reinstallation and shipping are paid by the owner.
A 30-gallon BuffMax tank for your zones, installed by AirGreen
Tell us about your project: we check the sizing, confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 19, 2026.