Raypak lists the 106A at 105 MBTU/h input and the 156A at 150 MBTU/h, both at 82% thermal efficiency and up to 70 GPM maximum water flow. The 106A suits smaller loads; the 156A provides roughly 43% more input for quicker recovery or a larger body of water. Raypak warns that these models cannot be sold in low-NOx markets including Southern California and Utah, so location is a gating question.
Raypak lists the 106A at 105 MBTU/h input and the 156A at 150 MBTU/h, both at 82% thermal efficiency and up to 70 GPM maximum water flow. The 106A suits smaller loads; the 156A provides roughly 43% more input for quicker recovery or a larger body of water. Raypak warns that these models cannot be sold in low-NOx markets including Southern California and Utah, so location is a gating question.
A compact comparison with one big caveat
These are purpose-built atmospheric gas heaters for above-ground pools and spas, with the 156A also positioned for some larger above-ground, spa and inground uses. Before comparing capacity, enter the installation ZIP code with an authorized seller or local professional. Emissions rules can disqualify both choices.
If the models are permitted, define the temperature rise and wait time. An above-ground pool can lose heat quickly through its exposed wall and water surface; gallons alone do not capture that load.
What the 45 MBTU/h difference means
At the same published 82% efficiency, the 156A can deliver more usable heat per hour. In idealized conditions, it therefore shortens recovery compared with the 106A. The exact time saved depends on water mass and ongoing loss.
That added input must be supported by the fuel system. Have a qualified gas professional calculate supply for the selected model and all other connected appliances. Never use a smaller gas line simply because it is already present.
Match circulation to the heater
Raypak lists 70 GPM as maximum water flow for both models, but proper operation also depends on maintaining adequate minimum flow and correct plumbing. Above-ground systems often use smaller pumps and piping, so this check is especially important.
Ask how the installer will verify flow after startup and whether a bypass is required. Keep the initial pressure readings and pump setting with the manual so later service has a baseline.
Ownership and winterization
An above-ground heater is still a combustion appliance. Provide the required clearances, prevent roof runoff, protect it from lawn chemicals and follow the manual for winter drainage. Freeze damage is preventable and is often outside warranty coverage.
Before purchase, identify a Raypak warranty service provider and download the current warranty document. Raypak notes that warranty applies only when the heater is installed according to local codes.
Which model wins?
Choose the 106A when the calculated load is small and its recovery time is acceptable. Step to the 156A when the added input produces a meaningful scheduling benefit and the gas system can support it. If local low-NOx rules prohibit the line, compare compliant low-NOx gas heaters or an electric heat pump instead.
Frequently asked questions
Can the Raypak 106A or 156A be used in Southern California?
Raypak's current product page states that the line cannot be sold in low-NOx markets including Southern California and Utah. Verify current local rules before ordering.
Is 156A twice as fast as 106A?
No. Its listed input is 150 versus 105 MBTU/h, about 43% higher, and real heat-up time also includes pool heat loss.
Can 156A heat an inground pool?
Raypak identifies it as an option for larger above-ground pools, spas and inground pools, but suitability requires a site-specific calculation.