Roots Blower Warranty

A roots blower warranty is a manufacturer's guarantee covering defects in material and workmanship for a specified period. Standard warranty is 12 months from commissioning or 18 months from shipment – whichever comes first. But warranty coverage has exclusions: damage from debris, blocked filters, misalignment, improper lubrication, and operator error are typically not covered.

Based on warranty claim records, the most common claims are for bearing failures (often from lubrication issues) and seal failures (from contamination). Understanding warranty terms and exclusions helps you protect your equipment investment and avoid claim denials.

This guide covers warranty terms, coverage, exclusions, claim process, and how to maximize warranty protection.

Table of Contents

• What Is a Roots Blower Warranty?

• Standard Warranty Terms

• What Is Covered

• What Is Not Covered (Exclusions)

• Extended Warranty Options

• Warranty Claim Process

• How to Maximize Warranty Protection

• Common Warranty Claim Issues

• Frequently Asked Questions

• Final Thoughts

What Is a Roots Blower Warranty?

A roots blower warranty is a written guarantee from the manufacturer that the equipment is free from defects in material and workmanship. If a defect occurs within the warranty period, the manufacturer will repair or replace the defective parts – subject to the warranty terms and exclusions.

Warranty purpose:

• Protects the buyer from manufacturing defects

• Ensures the equipment meets specifications

• Provides recourse for quality issues

• Encourages proper installation and maintenance

Based on warranty records, most claims are for:

• Bearing failures (40–50% of claims)

• Seal failures (20–30%)

• Rotor damage (10–15%)

• Gear failures (5–10%)

Standard Warranty Terms

Typical roots blower warranty:

• 12 months from commissioning

• OR 18 months from shipment

• Whichever comes first

What "commissioning" means:
The date the blower is first started up and put into operation. This should be documented and communicated to the manufacturer.

Why "from shipment" matters:
If the blower sits in a warehouse for 6 months, the warranty may expire before it is even installed. Specify warranty from commissioning – not from shipment.

Warranty start date:

• Document the commissioning date

• Notify the manufacturer of commissioning date

• Keep commissioning records for warranty claims

Warranty coverage period:

• Standard: 12 months after commissioning

• Extended: 24–36 months (optional, additional cost)

What Is Covered

Warranty typically covers:

• Defects in material (substandard materials)

• Defects in workmanship (manufacturing errors)

• Parts that fail due to manufacturing defects

• Repair or replacement of defective parts

• Labor for warranty repairs (may be limited)

Examples of covered defects:

• Bearing failure due to improper assembly

• Seal failure due to defective material

• Rotor casting defects

• Gear manufacturing defects

• Casing casting defects

What the manufacturer provides:

• Replacement parts (free of charge)

• Labor (may be limited to shop labor)

• Technical support for diagnosis

What Is Not Covered (Exclusions)

Standard warranty exclusions:

1. Operator error.

• Wrong rotation direction

• Operating above rated pressure or speed

• Improper startup procedure

• Operating with blocked discharge

2. Improper maintenance.

• Incorrect oil type or viscosity

• Oil contamination (water, dust)

• No oil (ran dry)

• Failed oil changes

• Failed filter changes

3. Debris or contamination.

• Dust entering through failed filters

• Foreign objects in blower

• Process contamination

• Condensate in blower (moisture damage)

4. Misalignment.

• Coupling misalignment

• Foundation issues

• Piping stress

5. Abuse.

• Overpressure

• Over speed

• Impact damage

• Improper storage

6. Normal wear.

• Bearings wear out (end of life)

• Seal wear (normal replacement)

• Rotor wear (normal erosion)

• Gasket degradation

7. Consequential damages.

• Lost production

• Lost profits

• Other equipment damage

• Labor costs beyond warranty labor

8. Third-party components.

• Motor (covered by motor manufacturer)

• VFD (covered by VFD manufacturer)

• Silencers (may have separate warranty)

Extended Warranty Options

Extended warranty:

• 24–36 months from commissioning

• Additional cost: 3–5% of blower price

• Extended coverage terms may differ

Benefits of extended warranty:

• Longer protection

• Budget certainty

• Peace of mind for critical applications

When to consider extended warranty:

• Critical process (plant can't tolerate downtime)

• New installation with limited track record

• High-value blower (large HP)

• Remote location with limited support

Questions to ask:

• What does extended warranty cover?

• What are the exclusions?

• What is the additional cost?

• How does it affect claim process?

Warranty Claim Process

Step 1 – Identify the problem.
What is the failure? Bearing failure? Seal leakage? Rotor damage? Gather evidence: photos, videos, operating logs.

Step 2 – Notify the distributor/manufacturer.
Contact the distributor or manufacturer. Provide blower model and serial number. Describe the failure and symptoms.

Step 3 – Provide documentation.

• Blower model and serial number

• Commissioning date

• Operating history (pressure, temperature, hours)

• Maintenance records (oil changes, filter changes)

• Photos and videos of the failure

• Operating conditions at time of failure

Step 4 – Manufacturer evaluation.
Manufacturer reviews the claim. May request additional information. May require return of failed parts for inspection.

Step 5 – Claim decision.
Approved: Replacement parts shipped. Warranty labor authorized. Denied: Reason provided (exclusion applies).

Step 6 – Repair or replacement.
Replace defective parts. Document the repair. Keep records for future reference.

How to Maximize Warranty Protection

1. Document commissioning date.
Notify manufacturer of commissioning date. Keep written records. Warranty starts from commissioning – not shipment.

2. Follow installation guidelines.
Proper foundation. Proper piping (flexible connectors). Proper alignment. Proper filtration. Improper installation voids warranty.

3. Follow maintenance schedule.
Use correct oil (ISO VG 150 or 220 synthetic). Change oil on schedule. Change filters on schedule. Document all maintenance.

4. Operate within limits.
Do not exceed rated pressure or speed. Do not run with blocked discharge. Do not run without oil.

5. Monitor operating conditions.
Record pressure, temperature, and hours. Early detection prevents major failure. Operating logs support warranty claims.

6. Use OEM parts.
Aftermarket parts may void warranty. Use genuine OEM parts for maintenance and repairs.

7. Keep records.
Commissioning records. Maintenance records. Operating logs. Photos of installation. All documentation supports warranty claims.

Common Warranty Claim Issues

How to avoid claim denials:

• Document commissioning date

• Follow maintenance schedule

• Keep maintenance records

• Use correct oil

• Change filters on schedule

• Install relief valve

• Document operating conditions

Frequently Asked Questions

1. What is the standard roots blower warranty?
12 months from commissioning or 18 months from shipment – whichever comes first. Standard industry warranty. Commissioning date is the first startup. Shipment date is when the blower leaves the factory. Whichever comes first determines warranty end date.

2. What does the warranty cover?
Defects in material and workmanship. Bearing failures due to manufacturing defects. Seal failures due to defective material. Rotor casting defects. Gear manufacturing defects. Casing defects. Repair or replacement of defective parts. Limited labor.

3. What is NOT covered by warranty?
Operator error, improper maintenance, debris/contamination, misalignment, abuse, normal wear, consequential damages (lost production, lost profits), and third-party components (motor, VFD). Read warranty exclusions carefully.

4. How long is an extended warranty?
24–36 months from commissioning. Additional cost: 3–5% of blower price. Extended coverage terms may differ from standard warranty. Ask for details before purchasing extended warranty.

5. How do I file a warranty claim?
Notify distributor or manufacturer. Provide blower model, serial number, commissioning date, operating history, maintenance records, photos, and descriptions. Manufacturer evaluates the claim. Approved: replacement parts shipped. Denied: reason provided.

6. What documentation do I need for a warranty claim?
Blower model and serial number, commissioning date, operating history (pressure, temperature, hours), maintenance records (oil changes, filter changes), photos and videos of the failure, and operating conditions at time of failure. Complete documentation improves claim approval.

7. Why was my warranty claim denied?
Common reasons: no commissioning record, no maintenance records, incorrect oil, dirty oil, blocked filter, misalignment, overpressure, no relief valve. Review warranty exclusions. Provide documentation for appeal.

8. Does the warranty cover labor?
Labor is typically covered for warranty repairs, but may be limited. Shop labor (at manufacturer) is usually covered. Field labor may not be covered or may be limited. Check warranty terms for labor coverage.

9. Does the warranty cover the motor?
Motor is typically covered by the motor manufacturer's warranty – not the blower manufacturer. Motor warranty is usually separate. Check motor warranty terms. Keep motor documentation.

10. Does aftermarket parts void the warranty?
Using aftermarket parts may void the warranty if they cause damage. Use genuine OEM parts for maintenance and repairs. If you use aftermarket parts, the manufacturer may deny claims related to those parts.

11. What is the commissioning date?
The date the blower is first started up and put into operation. Commissioning date should be documented and communicated to the manufacturer. Warranty starts from commissioning – not from shipment.

12. How do I document commissioning?
Record the date of first startup. Notify the manufacturer or distributor. Keep written records. Commissioning records are essential for warranty claims. Without commissioning date, warranty may be based on shipment date.

13. How does the warranty handle return shipping?
Return shipping for warranty parts is typically covered by the manufacturer. Return shipping for the entire blower may not be covered. Check warranty terms. Some manufacturers require the customer to ship the blower to the factory at their own cost.

14. What if the blower is stored for months before installation?
If the blower is stored, the shipment date may determine warranty end. Specify warranty from commissioning – not from shipment. Notify the manufacturer when the blower is commissioned. Keep commissioning records.

15. What is the difference between warranty and extended warranty?
Standard warranty: 12 months from commissioning or 18 months from shipment. Extended warranty: 24–36 months from commissioning (additional cost). Extended warranty terms may differ. Ask for details.

Final Thoughts

After decades of managing roots blower warranty claims, here is my practical advice:

Read the warranty terms. Understand what is covered and what is excluded. Zhanggu and other manufacturers provide clear warranty terms. Know the exclusions – operator error, improper maintenance, contamination, misalignment. Following the terms ensures coverage.

Document commissioning date. Warranty starts from commissioning – not from shipment. Notify the manufacturer when the blower is commissioned. Keep written records. Without commissioning records, warranty may expire before installation.

Follow maintenance schedule. Use correct oil. Change oil on schedule. Change filters on schedule. Document all maintenance. Warranty claims are often denied for improper maintenance. Proper maintenance is the best warranty protection.

The bottom line. Roots blower warranty protects you from manufacturing defects – but it does not cover operator error, poor maintenance, or contamination. Zhanggu and other manufacturers offer standard and extended warranty options. Read the terms. Document commissioning. Maintain properly. The warranty will serve its purpose – but proper operation and maintenance are the best protection.