Bosch Geothermal Review 2026: The Discontinued Greensource Line, the Current RP Series, and the Full Ratings Table

Search for "Bosch geothermal" and you get two stories that appear to contradict each other. Older buying guides and forum threads say Bosch's geothermal line is discontinued. Bosch's own catalog shows a current lineup for sale right now. Both stories are true, because they are about different products.

The Greensource series, the Bosch units actually sitting in basements across the country, is discontinued; Bosch lists every Greensource model on its own discontinued-products index. At the same time, Bosch currently sells a new generation of residential water-to-air geothermal heat pumps built on R-454B refrigerant: the RP, RP Split, RF, and RL series, with the RP036 on ENERGY STAR's live certified list.

This review keeps those two facts separate, because which one matters depends on which reader you are: the owner of a Greensource unit asking about parts and warranty, or a buyer deciding whether Bosch still belongs on the shortlist. The centerpiece is the AHRI ratings table for the current RP line, with all three rating conditions labelled, because that table is where a Bosch efficiency claim either holds up or falls apart.

The Short Answer

If you own a Bosch Greensource unit: your product line is discontinued. Bosch publishes no discontinuation date, only the statement "This is a discontinued product" on each model's page. Bosch keeps the documentation for discontinued models online, and its warranty document library, effective January 2024 to current, still lists the SM series alongside the current lines. Skip to the owner's section.

If you're shopping for a new system: Bosch is a live option, not a dead brand. Bosch's current residential water-to-air engineering-document index lists the RP, RP Split, RF and RL series; the RP Split and RF product pages both specify R-454B refrigerant. Skip to the ratings table and the verdict.

The confusion has a simple mechanism: a brand guide that recorded "Bosch discontinued its geothermal line" when the Greensource models went away reads as current until someone checks the replacement generation. Our own geothermal brands guide went through exactly that correction.

What Bosch Discontinued

Bosch maintains a public index of discontinued geothermal heat pumps. The Greensource family on it includes:

• Greensource BP and CP
• Greensource CDi Series SM (Rev A/B) and CDi Series SM (Rev C)
• Greensource Si Series CE
• Greensource i Series BP, WQ, SV, BC, SL
• Greensource CDi Series SM Split CS
• Greensource SV Split

That is the whole residential Greensource catalog, not one or two stragglers. If your unit says Greensource on the cabinet, it is a discontinued product.

Bosch does not publish a discontinuation date. The product pages state "This is a discontinued product" and nothing more. Any article that gives you a specific year for the Greensource line's end is supplying a number Bosch itself does not. Treat the line as out of production, with no official timeline attached.

The SM series, specifically

Owners search for the "Bosch geothermal SM series" because SM is what the model plate says. The designation belongs to the Greensource CDi Series SM, discontinued in both its Rev A/B and Rev C versions along with a Split CS variant. Two things soften that. Bosch's Greensource CDi documentation describes a "10-year limited parts and labor warranty," covered below, and Bosch's warranty document library still lists the SM series in its covered lineup, effective January 2024 to current. Discontinued does not mean disowned.

One warning for shoppers: a contractor quoting any Greensource model as new equipment in 2026 is selling leftover or replacement-market stock from a line Bosch no longer produces. Ask what warranty applies and how parts will be sourced before you sign.

What Bosch Sells Now

Bosch's current US residential water-to-air geothermal lineup, per its own product pages and engineering-submittal index, is:

• RP Series and RP Split. Bosch calls the RP Split "Bosch's premium, high efficiency, residential water source heat pump." Both run R-454B refrigerant, and the RP submittal sheet is the source of the ratings table below.
• RF Series. Described by Bosch as the "RF Series water-to-air residential geothermal heat pump." An RF070 closed-loop water-to-air configuration appears on ENERGY STAR's live certified list.
• RL Series. Listed on Bosch's engineering-submittal index for water-to-air water-source heat pumps.

Bosch also publishes brochures for current water-to-water models: the TW and the WT/WW, both R-454B. Water-to-water units serve radiant floors and hydronic systems rather than ducted air, and they are rated differently. The efficiency table in this article covers the water-to-air RP line only and says nothing about the water-to-water models. If radiant is your application, start with our water-to-water geothermal guide and pull the TW or WT/WW documents directly.

How to Read the Ratings Table

Bosch's RP engineering submittal publishes AHRI ratings under standard 13256-1, and the table carries three different rating conditions side by side. Getting Bosch's efficiency right means keeping them straight, because one of the three is not a geothermal rating at all.

The WLHP column exists because the same cabinets get installed in commercial buildings with boiler-and-tower water loops held at mild temperatures year round, and those mild temperatures produce flattering numbers. ENERGY STAR's geothermal categories are ground-loop and ground-water only; there is no WLHP category, because it is not geothermal. When a quoted Bosch figure looks too good against the rest of the market, check whether it is a WLHP number first. For the open-loop vs. closed-loop decision itself, the GWHP and GLHP columns are exactly the comparison; our open-loop vs. closed-loop guide covers what each demands from your property.

Three more terms and you can read the table like a pro. EER measures cooling, in BTU of cooling delivered per watt-hour of electricity; it is already a ratio, so no conversion applies. COP measures heating and is dimensionless: heat delivered divided by electricity consumed. Full load vs. part load: full load is the unit running at full compressor output, part load is reduced output, and in this table every part-load figure is higher than its full-load counterpart. On the closed-loop column Bosch also tests the two loads at different entering water temperatures (77°F cooling / 32°F heating at full load, 68°F / 41°F at part load); the water-loop and ground-water columns use one pair of temperatures for both loads. A spec quoted without its load condition cannot be compared with anything. Our efficiency ratings explainer covers the 13256-1 standard in depth.

The AHRI Ratings Table

These are the AHRI 13256-1 EER and COP ratings from Bosch's RP Series engineering submittal (June 2025 edition), for the copper water coil with ECM motor. Every EER and COP value published for that coil and motor combination appears below; the submittal's capacity, airflow and flow-rate columns are not reproduced, and it carries a separate cupro-nickel coil table with its own ratings. Every cell is EER (cooling) / COP (heating). The WLHP column is included so you can recognize those numbers when you meet them elsewhere; it is a building-loop rating, not a geothermal one.

Source: Bosch RP Series engineering submittal sheet, AHRI Ratings (13256-1), copper water coil and ECM motor. EER applies to cooling, COP to heating. Bold marks the closed-loop (GLHP) column, the condition that matches a typical residential loop field.

What the whole table tells you that a single quoted number never does:

Part load beats full load on every row. On a closed loop, the RP036 rates 18.5 EER / 4.0 COP at full load and 25.5 EER / 4.4 COP at part load. That is a wide enough spread that a headline figure taken from the part-load row will not describe the machine on a design-day, which is the reason to check which row a quoted number came from.

Efficiency falls as capacity rises. The RP024 and RP036 post 18.5 EER at closed-loop full load; the RP070 posts 17.0 EER at the same condition, with 3.8 COP full-load heating against 4.0 for the smaller cabinets. Bigger is not more efficient, one more reason correct sizing beats rounding up; our sizing guide covers that decision.

The open-loop column runs higher than the closed-loop column. Ground water at a steady 59°F/50°F is a thermodynamic gift: the RP036 rates 24.0 EER / 5.0 COP at open-loop (GWHP) full load versus 18.5 EER / 4.0 COP at closed-loop (GLHP) full load. Whether an open loop is available to you is a property question, not a catalog question.

One footnote from the same document: the submittal also carries a separate ratings table for a cupro-nickel water coil, a different coil option with its own figures. If your quote specifies cupro-nickel, ask for that table.

A cross-brand comparison holds only when the condition and the load match on both sides, and each manufacturer publishes under its own configurations. We keep those comparisons, with each brand's conditions attached, in the brands guide and the most-efficient heat pump roundup, alongside our WaterFurnace, ClimateMaster and GeoStar reviews.

ENERGY STAR Certification

Bosch's current line appears on ENERGY STAR's live certified geothermal list. Certification records can outlast a product's time on the market, so the evidence that Bosch is actively selling is its current product pages and engineering-document index rather than the certified list; what the list adds is verified performance data. Two entries worth knowing:

• Bosch-Geo CP/RP Split, model RP036-1CSN-*****A, open-loop water-to-air, listed at 26.4 EER and 4.9 COP with "ENERGY STAR Certified: Yes." The same model number is listed at 21.4 EER / 4.3 COP on a closed loop.
• Bosch RF070-1VTN, listed as "Type: Closed Loop Water-to-Air" on the live certified results.

The detail that trips people up: a different product, not a different measurement. The ENERGY STAR entry carrying 26.4 EER / 4.9 COP is filed under the model name CP/RP Split, model number RP036-1CSN-*****A. The RP submittal's open-loop (GWHP) full-load row reading 24.0 EER / 5.0 COP is for the packaged RP036. A split system and a packaged system are two different machines that share a capacity code, so the two figures were never describing the same unit.

The same ENERGY STAR dataset shows how much spread sits under one capacity code. Searching its certified geothermal records for Bosch RP036 returns closed-loop entries at 19.9, 20.1, 20.7, 21.4, 21.8 and 22.0 EER and open-loop entries at 24.4, 24.6, 25.8, 26.4, 26.5 and 27.0 EER, spread across the CP and CP/RP Split model names. Match the full model number, not the three digits in the middle of it, and quote every figure with its source, its loop type and its model name attached.

What the Warranty Actually Says

Two things about the Bosch geothermal warranty are on the record, both from Bosch's own pages.

First, the coverage statement. Bosch's Greensource CDi SM (Rev C) documentation describes a "10-year limited parts and labor warranty" that "covers all components incorporated into the unit cabinet at the time of manufacture." That parts-and-labor wording is from the discontinued Greensource CDi SM documentation. The current RP submittal states a 10-year limited parts warranty and a 10-year limited compressor warranty; it does not carry the labor language. Warranty terms are per document and per model, so compare the document that applies to the exact unit you are quoted rather than the series headline.

Second, the coverage map. Bosch's product warranty library for geothermal heat pumps spans the "RF / BP / CE / RP / SM / TW Series" with an effective date of "2024/01 - Current." That list mixes the current RF, RP, and TW lines with the discontinued BP, CE, and SM series. The warranty library did not drop the Greensource generation when production did.

That is where the published record stops. Registration requirements, exclusions, labor-hour limits, and transferability to a home's next owner are governed by the model-specific warranty document, not by any summary. Before relying on any coverage claim, pull the document for your exact model and vintage from Bosch's warranty library and read it. Our geothermal warranty guide explains which clauses to check first, and our repair guide shows what an uncovered service call costs.

What a Bosch Geothermal Heat Pump Costs

"How much does a Bosch geothermal heat pump cost" has a factual answer, and it is not a dollar figure: Bosch publishes no prices. No MSRP on the product pages, no published dealer price list. Any dollar figure attached to a Bosch RP or RF unit online is a third party's estimate or a single dealer's quote, not a Bosch number, and this review is not going to invent one either.

You will also read that Bosch is "the budget brand" of geothermal. No published data supports ranking Bosch against WaterFurnace, ClimateMaster, or anyone else on price, and Bosch publishes no market-share figures that would support any ranking claim. The only price comparison that means anything is between written quotes for your house.

What you can actually do with the cost question:

1. Get quotes against exact model numbers. "A Bosch system" tells you nothing; "an RP048, copper coil, on a closed loop" is a quote you can compare.
2. Price the loop and the labor separately from the cabinet. Loop type, drilling or trenching conditions, and local labor are quoted separately from the equipment on any brand, and they are where two quotes for the same Bosch model diverge. Our installation cost guide breaks down the full stack, the payback period guide shows whether a quote pencils out, and the financing options comparison covers spreading the cost.
3. Budget without the federal tax credit. The 30% residential credit under IRC §25D applied only to property placed in service through December 31, 2025, and is not available after that date. Any cost article that nets 30% off is working from a dead assumption; details in our federal tax credit guide.

If You Own a Greensource Unit

Discontinued means Bosch stopped producing your unit, not that your documentation vanished or your warranty evaporated. The current state of things for a Greensource owner:

Your documentation is still published. Bosch keeps the discontinued models, from the BP and CP through both CDi SM revisions, the i Series variants, and the split models, on a public discontinued-products index with their pages intact.

The warranty library still lists your series. The geothermal warranty document library covering "RF / BP / CE / RP / SM / TW Series" is marked effective January 2024 to current, and the BP, CE, and SM in that list are Greensource-era series. The model-specific document is there to download. Whether a particular unit is still inside its term is a separate question that depends on its installation date, its model and the terms of the document that applied when it was sold, so read the document for your own unit rather than assuming the series listing answers it.

There is no published clock. Bosch publishes neither a discontinuation date for the Greensource line nor a parts-support end date. That cuts both ways: no official deadline looms over you, and no official promise protects you. Keep maintenance records, and know your model and serial before you need them.

When the unit eventually ages out, the expensive half of your system stays. The ground loop is a separate asset from the cabinet, and replacing an old heat pump on an existing loop is a routine, far cheaper job than a full installation. Bosch's current water-to-air line is one candidate for that swap; so is every other brand's. Our heat pump replacement guide walks through the process, and the system lifespan guide helps you judge how much life your unit has left.

Should You Buy a Bosch in 2026?

Bosch belongs on a 2026 shortlist. The line is current-generation: R-454B refrigerant on the RP, RP Split and RF series, published AHRI 13256-1 ratings, and live ENERGY STAR listings including the CP/RP Split RP036-1CSN (open loop, 26.4 EER / 4.9 COP) and an RF070 closed-loop configuration. The published closed-loop numbers for the RP line run 17.0 to 18.5 EER with 3.8 to 4.0 COP at full load across RP024 through RP070, rising to 23.0 to 27.0 EER and 4.2 to 4.4 COP at part load. Those are the figures to hand your installer, condition and load attached.

No published data says whether Bosch is cheaper than the competition, how its market share compares, or how its reliability record stacks up against other brands. Claims on any of those are running ahead of the evidence.

The buying process that protects you, with Bosch or anyone:

1. Confirm your property first. Loop type determines which column of the ratings table you will live in. Start with whether your property suits geothermal.
2. Quote exact model numbers and demand the matching rating. Installing a closed loop? The GLHP figures are your figures. An installer quoting the open-loop or, worse, the water-loop number for a closed-loop job is comparing apples to a different orchard.
3. Get the warranty document, not the warranty sentence. On the current RP line the headline is 10-year parts and 10-year compressor coverage, not labor, and any headline is only as good as fine print you have not read yet.
4. Weight the installer heavily. Loop design, load calculation, and commissioning move real-world performance more than the badge on the cabinet. Our installer certification guide lists the credentials to ask about.

Frequently Asked Questions

Is Bosch geothermal discontinued? The Greensource line is discontinued; Bosch's geothermal business is not. Bosch lists every Greensource series (BP, CP, CDi SM Rev A/B and Rev C, Si CE, the i Series, and the split variants) on its discontinued-products index, and currently sells the R-454B RP, RP Split, RF, and RL water-to-air lines plus TW and WT/WW water-to-water models.

What is the Bosch geothermal SM series? SM is the Greensource CDi Series SM, sold in Rev A/B and Rev C versions plus a Split CS variant, all discontinued. Bosch's warranty document library, effective January 2024 to current, still lists the SM series among its covered lines.

How much does a Bosch geothermal heat pump cost? Bosch publishes no pricing, no MSRP, and no dealer price list, so every specific dollar figure online is a third-party estimate. Installed cost is driven mostly by loop type, drilling conditions, and labor rather than the unit. Get written quotes against exact model numbers and compare them using our installation cost guide.

What is the Bosch geothermal warranty? Bosch's Greensource CDi documentation describes a "10-year limited parts and labor warranty" that "covers all components incorporated into the unit cabinet at the time of manufacture." The current RP submittal states a 10-year limited parts warranty and a 10-year limited compressor warranty, without the labor language. Bosch's warranty library covers the RF, BP, CE, RP, SM, and TW series effective January 2024 to current. Registration requirements, exclusions, labor limits, and transferability are set by the model-specific warranty document, so download yours before relying on the headline term.

How efficient are Bosch geothermal heat pumps? On a closed loop (GLHP), the current RP line rates 17.0 to 18.5 EER and 3.8 to 4.0 COP at full load depending on model (RP024 through RP070), and 23.0 to 27.0 EER with 4.2 to 4.4 COP at part load, per Bosch's AHRI 13256-1 submittal for the copper coil with ECM motor. Open-loop (GWHP) ratings run higher: the RP036 posts 24.0 EER / 5.0 COP at full load. Ignore any WLHP figure you see quoted; that is a building-loop rating, not geothermal.

Is Bosch geothermal ENERGY STAR certified? Yes. The Bosch-Geo CP/RP Split RP036-1CSN appears on ENERGY STAR's certified geothermal list as an open-loop water-to-air unit at 26.4 EER / 4.9 COP, and a Bosch RF070 closed-loop water-to-air configuration appears on the live certified results. Certification is per model number and loop type, so check the full model number on the quote you are given.