Precision engineering for zero emergencies

Diesel Generators Repairs

Usually used when there is an emergency situation, when generators fail – it is catastrophic. At Mawdsleys, we don’t take chances with power. We provide both standby and prime power diesel generator repair, overhaul, and inspection services —working across every major sector. Whether your generator is mission-critical for production, safety, or just keeping operations moving—we make sure it is reliable when it matters most.

An image of a generator

Leading causes of generator breakdowns

A generator is only as good as its last service. Here are the faults we see time and again—each avoidable with the right maintenance:

  • Battery Failure: The #1 cause of failure. Sulphate buildup on battery plates prevents sufficient current flow. Without power from the battery, the generator won’t start—simple as that.
  • Low Coolant Levels: Coolant drops too low, the generator overheats, and an auto-shutdown kicks in. It’s a silent killer. Visual checks prevent this.
  • Fuel Contamination: Diesel goes stale. Stagnant fuel grows bacteria, gums filter, and starves the engine. If your generator smells bad or runs weak, you’ve got dirty fuel.
  • Under Loading: Generators are built to work. Run them idle or at low load too often, and internal damage builds up. Then they fail under full demand—when you need them most.
  • Human Error: Someone leaves auto-start switched off. It happens. The result? A blackout.

Proactive Generator Servicing & Inspection

Nearly every cause of generator failure can be prevented with scheduled maintenance. That’s why we recommend a full generator service every 6 months—or every 400 operating hours, whichever comes first. Generator maintenance is cheaper than emergency generator repair.

Our thorough inspection includes:

  • Fuel polishing and testing
  • Load bank testing
  • Coolant, oil, and water checks
  • Control panel diagnostics
  • Battery terminal cleaning
  • Alternator, exhaust, and engine checks
An image of our warehouse

A Workshop Built to Keep You Running

Some jobs need the workshop. When we can’t fix your generator on site—or if it’s more efficient to work offsite—we’ll transport your equipment to our fully equipped, in-house workshop.

Here’s what that means:

  • Full stock of genuine spares and parts
  • Skilled engineers with decades of experience
  • Rapid turnaround on overhauls and repairs
  • Delivery and installation after the service

Our facilities are built for speedy, precision, and reliable generator repairs. Because in your business, downtime isn’t an option.

Case Studies

This is why

1. Speed of service

Reducing your downtime is our main priority. That’s why, from the moment you call to the final report, we move fast. No delays. Just results.

2. High-quality service

With over 100 years experience, we’ve built a reputation on precision, excellence, and constant improvement. You expect the best—we deliver it.

3. One-stop shop

The vast experience of our staff, combined with our state-of-the-art workshop, provide us with flexibility. We do not only repair – we manufacture.

4. ATEX motors specialists

Repairing all types of ATEX motors. We are an AEMT Ex Registered Repairer recognised for our quality systems and professional repair standards.

Diesel Generator Repair FAQ

How do I know that my generator needs repair?

The early signs indicating generator repairs are frequent power fluctuations, increased vibration, higher temperature, increased fuel consumption, and increased noise.

How often should I service my generator?

The minimum frequency of generator service should be 6 months or 400 working hours.

How much does a generator repair cost?

The generator repair costs will depend on the severity of the issues. It is certain that if it fails whilst being used the costs will be far greater than if it is maintained well. Get in touch for your quote today.

Contact Mawdsleys Today for Swift Motor Support