FHP/Bosch Model Family Guide: Which Series Do You Have?
FHP and Bosch have sold water-source and geothermal heat pumps under dozens of two- and three-letter series names since the 1990s — AP, BP, CA, EM, ES, SM, TW, and many more. If you're staring at a data plate trying to figure out what you actually have, the series prefix on the model number is the fastest way in. This guide sorts every FHP/Bosch series by era and status so you can place your unit and know what to expect from it — parts availability, refrigerant, warranty terms.
(For the letter-by-letter breakdown of the model number itself, see our FHP/Bosch model & serial number decoder.)
Currently in production
As of this writing, four series are still active — all switched from R-410A to the lower-GWP refrigerant R-454B on 1/1/2025, with the model names unchanged through the changeover:
| Series | Type | Sizes | Warranty |
|---|---|---|---|
| CA | Console (in-room water-source heat pump) | ¾–1½ ton | 5 yrs compressor / 1 yr other parts |
| TW | Water-to-water condensing section | 2–5 ton, and 10 ton | 10 yrs |
| WT | Water-to-water condensing section | 2–6 ton | 5 yrs compressor / 1 yr other parts |
| WW | Water-to-water condensing section | 10–35 ton | 5 yrs compressor / 1 yr other parts |
If your unit is a CA, TW, WT, or WW built after 1/1/2025, confirm which refrigerant it's charged with before ordering refrigerant-side parts — the model name alone doesn't tell you.
Discontinued 2024 — still recent, parts widely available
| Series | Type | Active years | Notes |
|---|---|---|---|
| SM (GreenSource CDi) | Vertical/horizontal package, 2-stage | 2013–2024 | Three controller revisions (A/B/C) over its life — rev C added a Bluetooth/EasyStart app controller |
| ES (two-stage) | Vertical/horizontal package, 2-stage | through 2024 | Models ES025/035/049/061/071 — don't confuse with the older single-stage ES line below |
| LV | Vertical/horizontal package, single-stage | 2014–2024 | Counterflow config dropped 2018, splits dropped 2019 |
| SV (GreenSource) | Vertical/horizontal/counterflow package | 2014–2024 | Counterflow dropped 2018, splits dropped 2019 |
| LM | Commercial package/split, 2-stage | 2014–2024 | Counterflow config dropped ~2018 |
| CE | Package/split, 2-stage | 2013–2024 | Split config discontinued 2014; condensing-section-only variant ran 2014–2019 |
| EP | Single-stage | through 12/2024 | |
| BP | Package, single-stage | 2011–2024 | ½–5 ton; some sizes (BP007/009/015/060) dropped earlier, 9/2018 |
Older R-410A lines (discontinued 2013 and earlier)
| Series | Type | Active years | Notes |
|---|---|---|---|
| AP (Aquarius II) | Package/split, 2-stage | through 2013 | 2–6 ton |
| AU | Package, 2-stage | discontinued | Decorative-cabinet version of the two-stage ES |
| BC | Console | through 2018 | ¾–1½ ton |
| CP | Package, single-stage | through 2013 | 2–6 ton |
| EC (small sizes) | Package/split, single-stage | ½–6 ton discontinued 2013 | Larger 7–30 ton EC units were still in production as of 2016 — don't assume all EC is obsolete |
| ES (single-stage) | Package, single-stage | through 2013 | Models ES018/024/030/036/042/048/060/070 |
| EV | Package/split, single-stage | discontinued | 1½–6 ton |
| TA | Package/split, 2-stage | through 2013 | 2–6 ton |
Legacy R-22 lines (1990s–2000s)
If your unit's series appears here, it predates the 2010 EPA phase-down of R-22 production and is almost certainly running original refrigerant charge from installation. These are the oldest units we still support with parts.
| Series | Type | Active years |
|---|---|---|
| EM (Energy Miser) | Package/split, single-stage, ½–30 ton | discontinued |
| GO | Package, single-stage (4–5 ton multi-step) | 1996–2003 |
| GS (Geo-Saver) | Package/split, single-stage | 1996–2008 |
| GT (Geo-Thermal) | Package/split, single-stage | 1996–2008 |
| HE | Package/split, single-stage (HE007–HE214) | 1996–2008 (docs date to the 1990s) |
| LT (Lo-Temp) | Package/split, hybrid (LT010–LT090) | discontinued |
| SE (Super Efficiency) | Package/split (SE022–SE063) | discontinued |
| SL (Super Lo-Temp) | Package/split, residential | 1990s; a separate light-commercial SL (6/8/10 ton) ran ~2014–7/2018 |
| SX | Package/split (single-stage under 3.5 ton, 2-stage 4 ton+) | 1992–1997 |
| VS (Vertical Stack) | Vertical, McQuay cabinet | discontinued, 1–2 ton |
| WH | Water-to-water condensing section, 1.5 ton | discontinued when R-410A came into use |
| CS | Console (CS009–CS018) | through 2019 |
Zoning and controls
EnviroZone is a zoning control system, not a heat pump — if that's what's on your paperwork, you're looking at a controls product, not a unit series. Genesis VI control boards were used on SX and GO units through the mid-to-late 1990s and are no longer manufactured — see our Genesis VI blink-code guide if you're troubleshooting one.
Not sure which one you have?
Send us your model number — even a partial one — along with a photo of the data plate if you have it, and we'll confirm the series and pull the right parts.
NOTE: Unless we sold you the unit, we cannot file warranty claims for parts sold by other dealers, reps or contractors. We can help if you'd like to purchase the replacement part from us.
Frequently Asked Questions
Which FHP/Bosch series are still in production?
Four series are currently active: CA (console), TW, WT, and WW (all water-to-water condensing sections). All four switched from R-410A to the lower-GWP refrigerant R-454B on 1/1/2025, with the model names unchanged through the changeover.
How do I know if my CA, TW, WT, or WW unit runs R-410A or R-454B?
The model name doesn't change across the changeover, so the name alone won't tell you. If your unit was built after 1/1/2025, confirm which refrigerant it's charged with before ordering refrigerant-side parts.
Which FHP/Bosch series were discontinued in 2024?
SM (GreenSource CDi), two-stage ES, LV, SV (GreenSource), LM, CE, EP, and BP — all still recent enough that parts are widely available.
What is EnviroZone?
EnviroZone is a zoning control system, not a heat pump. If that's what's on your paperwork, you're looking at a controls product, not a unit series.
What is a Genesis VI control board?
Genesis VI control boards were used on SX and GO units through the mid-to-late 1990s and are no longer manufactured.
How old could a unit with an R-22 series designation be?
If a unit's series falls in the legacy R-22 lines (EM, GO, GS, GT, HE, LT, SE, SL, SX, VS, WH, or CS through 2019), it predates the 2010 EPA phase-down of R-22 production and is almost certainly running its original refrigerant charge from installation — these are the oldest units we still support with parts.
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