Therm Products

Therm Products spa heaters and replacement heating assemblies

Here you will find heating hardware from Therm Products, a name associated with flow-through heater assemblies for spas, hot tubs and small heated pools. A flow-through heater is the component that sits in the plumbing loop after the pump and filter: water passes through a metal tube, an immersed element warms it on the way past, and the control system switches the element on and off to hold the set temperature. Because the element is in direct contact with pool or spa water the whole time the system runs, it is one of the parts most likely to need replacing over the life of a spa.

The range listed here is built around assemblies supplied with union connections, so the heater can be isolated and removed without cutting into the pipework. That makes a like-for-like swap the usual repair route once an element has failed or a housing has corroded.

The 2 kW heater with Incoloy element

The assembly currently listed is the 2 kW heater with an Incoloy element and 2-inch unions, part number C2200-0812ET-G. Three details in that description do the work when you are matching a replacement:

• 2 kW output — the electrical rating of the element, which determines how quickly the water warms and what the circuit and control gear must support. Fitting a heater of a different rating is not a neutral change; it affects current draw and the way the controller behaves.
• Incoloy element — a nickel-iron-chromium alloy widely used for immersion elements because it resists the pitting and scaling that affect plainer materials in treated water.
• 2-Zoll-Verschraubungen — the connection size at each end of the heater body. The union nut diameter is what you measure, not the internal bore of the pipe, and it is the single most common reason a replacement does not fit.

The suffix on a part number such as C2200-0812ET-G usually encodes variations in the sensor and terminal arrangement, so it is worth quoting the code from the label on the old heater in full rather than ordering on wattage alone.

How to identify the right replacement

Before ordering, work through the heater you are removing rather than the spa model, because many cabinets were built with more than one heater option over the years. Useful checks include:

• The label on the heater body — the part number, voltage and kW rating are normally printed or stamped on the tube or on the terminal cover.
• Verschraubungsgröße — measure across the threaded collar; 1.5-inch and 2-inch assemblies look similar at a glance but will not interchange.
• Overall length between unions — the heater has to bridge the existing gap in the pipework without forcing the pipes out of line.
• Sensor and thermostat pockets — note how many wells the housing has and what sits in them, so the temperature sensor and high-limit from your control pack can be reused.
• Terminal orientation — check which way the studs or spade terminals face in the cabinet, as clearance inside a spa skirt is often tight.

If the element has failed through dry firing or heavy scaling, inspect the rest of the loop at the same time. Blocked filters, a tired pump impeller or a closed valve reduce flow and are frequently the underlying cause rather than the heater itself.

Looking after a spa heater

Element life depends mostly on water chemistry and flow. Water that is aggressive, out of balance or high in dissolved solids attacks the element surface, while hard water leaves a scale layer that insulates the element and makes it run hotter than intended. Keeping pH and alkalinity in range, rinsing or replacing the filter on schedule and never running the heater with air in the plumbing are the practical steps that extend service life. Electrical work on a heater should always be carried out with the supply isolated and in line with local wiring regulations.

Therm Products at PoolParthub.com

Here we list Therm Products heating hardware for spa and hot tub circuits, including the 2 kW Incoloy assembly with 2-inch unions. The focus is on parts that are ordered as direct replacements, where the part number on the old component tells you exactly what to fit.

Spa heaters are a part people buy once a system has already stopped heating, so clear part numbers and connection sizes matter more than anything else. If you are unsure which variant your cabinet was built with, send the code from the heater label along with the union size and the distance between connections, and the match can be checked before you order.