Rheem R96V: the minimum static pressure nobody mentions
The published range runs from 0.18 to 1.0 inches water column, so there is a floor as well as a ceiling. Plus the eight fields inside R96VA0402317MSA.
What this means
Rheem publishes both a minimum and a maximum external static pressure for the R96V. The maximum is 1.0 inches water column on every model; the minimum runs from 0.18 on the 40 size to 0.28 on the larger ones. A duct system below the minimum is outside the published range in the same way one above the maximum is.
Equipment and model context
Rheem Prestige Series R96V two-stage variable speed gas furnaces
- R96VA0402317MSA at 42,000 BTU per hour
- R96VA0602317MSA, R96VA0702317MSA, and R96VA0702521MSA
- R96VA0852521MSB, R96VA1002521MSA, and R96VA1152524MSA
The R96V series as published in the Rheem Prestige Series specification sheet for United States and Canadian models. Figures are per model, and a neighbouring size in the same series carries different numbers, so the model on the plate is the one to read against.
What this guide covers
- A furnace replacement being specified from the old cabinet width and input rate alone.
- A commissioning sheet with a static pressure reading and no range to judge it against.
- A temperature rise measurement taken without knowing which firing rate produced it.
What changes the answer
- The published static pressure range has a floor as well as a ceiling, and only the ceiling is widely quoted.
- The model number encodes cabinet width and airflow class, which decide the physical fit.
The floor on the static pressure range
Every discussion of furnace static pressure is about restriction: a dirty filter, an undersized return, a closed damper. Rheem's table publishes the other end as well. Minimum external static pressure is 0.18 inches water column on the 40 size, 0.20 on the 60, 0.23 on the 70 sizes, and 0.28 on the 85, 100, and 115. Maximum is 1.0 inches across the range.
A furnace running below its minimum is moving more air than the design assumed for the heat exchanger it is passing over. The temperature rise falls, and the published rise range is what the commissioning check is measured against, so the two figures belong together.
In practice a reading below the floor points at a duct system with less resistance than the equipment was selected for, which is a different investigation from a reading above the ceiling. Recording which side of the range a system sits on is what makes the next step obvious.
Reading R96VA0402317MSA
Rheem prints the decode on the specification sheet. R is Rheem and 96 is the efficiency. V is the motor and design series with A as the first design, 040 is the input, 2 is the two-stage designation, 3 is the airflow class, and 17 is the cabinet width. M is multi-position, S is standard configuration, and the final letter is the revision.
Two of those fields decide whether a replacement fits. Cabinet width is 17 for 17.5 inches, 21 for 21.0, and 24 for 24.5, and the airflow class is 3 for up to 3 tons and 5 for up to 5 tons. A furnace of the same input in a different width is a plenum modification rather than a swap.
The input field is a BTU per hour code rather than the figure itself: 040 is 42,000, 060 is 56,000, 070 is 70,000, 085 is 84,000, 100 is 98,000, and 115 is 112,000. Reading 040 as forty thousand is close enough to be believed and wrong by two thousand.
Two firing rates, two temperature rise ranges
Low fire on this series is 70 percent of high fire on every model: 29,400 against 42,000 on the 40, 78,400 against 112,000 on the 115. The furnace is a two-stage appliance, so a measurement taken at one rate does not describe the other.
Rheem publishes separate temperature rise ranges to match. The 40 size is 20 to 50 degrees Fahrenheit on high fire and 15 to 45 on low. The 115 is 45 to 75 on high fire and 35 to 63 on low. Every model has its own pair.
So a rise measurement is only interpretable alongside two other facts: which model it was taken on and which stage was running at the time. A reading of 40 degrees is inside the high fire range on the 40 size and below the high fire range on the 115.
What the thermostat has to be
Rheem states the furnace is compatible with single or two stage thermostats, and that a two stage thermostat is recommended for optimal performance. That is a compatibility statement rather than a requirement, and it explains a common outcome.
A two-stage furnace on a single-stage thermostat still has two firing rates. What it loses is the thermostat's ability to call for the second one directly, so the control decides when to step up on its own timing rather than on a room signal.
For a house replacing a single-stage furnace and keeping the thermostat, that is the part of the upgrade that quietly does not arrive. It is a cheap thing to fix at installation and an awkward one to notice afterwards.
| Input size | Minimum | Maximum |
|---|---|---|
| 040 | 0.18 in. w.c. | 1.0 in. w.c. |
| 060 | 0.20 in. w.c. | 1.0 in. w.c. |
| 070 | 0.23 in. w.c. | 1.0 in. w.c. |
| 085 | 0.28 in. w.c. | 1.0 in. w.c. |
| 100 | 0.28 in. w.c. | 1.0 in. w.c. |
| 115 | 0.28 in. w.c. | 1.0 in. w.c. |
| Field | What it says |
|---|---|
| R96 | Rheem, 96 percent efficient |
| V and A | Motor and design series, A being the first design |
| 040 to 115 | Input code, 040 being 42,000 BTU per hour |
| The digit 2 | Two-stage |
| 3 or 5 | Airflow to three tons or to five |
| 17, 21, or 24 | Cabinet width in inches, 17.5, 21.0, or 24.5 |
A static pressure figure and a temperature rise figure are both judged against per-model published ranges, and one of them changes with the firing stage. Recording the model and the stage is what makes the numbers usable later.
- Model numberSets both published ranges
- Firing stage at the timeHigh fire and low fire have separate rise ranges
- External static pressureJudged against a floor and a ceiling
- Temperature riseJudged against the range for that model and stage
Questions people ask about this
Does a furnace have a minimum static pressure?
The R96V does. Rheem publishes a minimum external static pressure of 0.18 to 0.28 inches water column depending on input size, alongside a maximum of 1.0 inches. A duct system below the floor is outside the published range just as one above the ceiling is.
What does R96VA0402317MSA mean?
Rheem, 96 percent efficient, V motor and A first design series. Then 040 input at 42,000 BTU per hour, 2 for two-stage, 3 for airflow to three tons, and 17 for a 17.5 inch cabinet. M is multi-position, S standard configuration, and A the first release revision.
What is the low fire input on a Rheem R96V?
Seventy percent of high fire on every model in the series. The 40 size fires 42,000 BTU per hour high and 29,400 low; the 115 fires 112,000 and 78,400.
Does an R96V need a two-stage thermostat?
Rheem states it is compatible with single or two stage thermostats and recommends a two stage thermostat for optimal performance. On a single-stage thermostat the furnace still has two rates, but the room signal cannot call for the second one directly.
What temperature rise should an R96V have?
It depends on the model and the firing stage. The 40 size is published at 20 to 50 degrees Fahrenheit on high fire and 15 to 45 on low; the 115 size is 45 to 75 and 35 to 63. A reading is only meaningful against the pair for that model.
Evidence recordHow this page was checked
service manual, operation manual · checked 2026-09-07
Every technical claim above was written from primary documentation held in the HVAC Bench evidence record: Rheem technical literature. Where a source limits a definition to certain models, test conditions, or product classes, that limit is repeated here rather than generalised.
- Documentation class
- service manual, operation manual
- Scope of the definition
- Rheem Prestige Series R96V two-stage variable speed gas furnaces
- Last checked
- 2026-09-07