Bosch's residential warranties are competitive with Rinnai and Navien on the gas tankless side. The 15-year Greentherm heat exchanger warranty is one of the longest in the residential gas tankless category. Other product families have shorter coverage matched to their use case.
| Product | Heat Exchanger / Tank | Parts | Labor |
|---|---|---|---|
| Greentherm condensing (9000, 9900, 9999) | 15 years | 5 years | 1 year |
| Greentherm 5300 / 7.2 (mid-tier / non-condensing) | 10 years | 5 years | 1 year |
| Greenstar combi (100, 131, 151) | 10 years | 5 years | 1 year |
| Tronic POU mini-tank | 6 years (tank) | 1 year parts | — |
| Tronic Heat 3000 electric tankless | 10 years (chamber) | 1 year parts | — |
| Commercial install (any) | 5 years | 3 years | 1 year |
Warranty lookup
You need the model number and serial number from the data plate. Then:
- Online: bosch-homecomfort.com / warranty section
- Phone: 1-866-642-3198 — Bosch Thermotechnology US customer service
- Through your installer: Bosch-trained installers submit claims via distributor channel
Registration
Bosch recommends registering within 30 days of installation via bosch-homecomfort.com. Without registration, warranty defaults to manufacture date as start — losing up to 6-12 months coverage if the unit was in inventory. Always register.
Filing a claim
- Note the error code if displayed
- Photograph the data plate
- Call 1-866-642-3198 or have your Bosch-trained installer call
- Bosch dispatches parts to a trained installer (not direct to homeowner)
- Labor coverage applies only in year 1
What voids the warranty
- No annual descaling in hard-water regions (over 11 grains per gallon)
- Installation by non-licensed plumber in jurisdictions requiring permits
- Improper venting (mixed manufacturers, undersized diameter, exceeded length)
- Use of LP unit on natural gas (or vice versa) without conversion kit
- For Greenstar combi: improper hydronic install (missing primary/secondary loop, expansion tank, air separator)
- For Tronic Heat electric: undersized electrical service causing repeated trip events
Compared to other brands
Bosch's 15-year Greentherm heat exchanger warranty matches Rinnai Sensei (15-year) and Navien NPE-A2 (15-year). The 10-year Greenstar combi warranty is competitive with Navien NCB and Noritz NRCB. Tronic POU's 6-year tank warranty is standard for the point-of-use segment.
Bottom line
Register inside 30 days, save installer invoice and descaling receipts, use Bosch-trained installers for in-warranty work. The 15-year Greentherm heat exchanger warranty is genuinely industry-leading — defend it with documented maintenance.