Mechanical Engineer (Contractor)
Octopus EnergySlough (GB), United Kingdom
CONTRACTOR
Posted June 10, 2026
£27k - £29k· Est.
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Job Description
Octopus Energy's R&D team in Slough is developing the next generation of heat pump systems and hydraulic products that surround them.
Key Responsibilities
- Design, build and commission hydraulic test rigs and prototype products that integrate with heat pumps (buffer tanks, hot water cylinders, heat exchangers, circulation and modulation hardware, and similar).
- Carry out hands-on assembly and plumbing of water-side and refrigerant-adjacent systems - pipework, fittings, pumps, valves, sensors and controls.
- Instrument rigs with temperature, flow and pressure measurement, and run structured test campaigns to characterise both systems and components performance.
- Diagnose and troubleshoot hydraulic, thermal and mechanical issues on live systems, and feed findings back into the design.
- Work closely with the wider R&D team to iterate designs quickly, balancing performance, cost, manufacturability and serviceability.
- Produce clear documentation: test plans, build instructions, results write-ups and design records.
Requirements
- Degree in Mechanical Engineering (or a closely related discipline).
- Minimum 5 years' relevant experience in an R&D, product development or test environment.
- Demonstrable heat pump knowledge - you understand how heat pumps work, their operating envelopes, and how the hydraulic system around them behaves (flow, temperature, ΔT, defrost, modulation, etc.).
- Strong hands-on experience - this is the most important requirement. You can build, plumb, commission and fault-find systems yourself, not just specify them. Practical plumbing and pipework skills are essential.
- Experience working with hydraulic systems - pumps, valves, heat exchangers, tanks, pipework and the behaviour of water-side circuits.
- Comfortable instrumenting rigs and interpreting test data to draw engineering conclusions.
- CAD proficiency for designing rig components and prototype parts.
- Able to work independently and using own initiative on-site in Slough and move quickly in a fast-paced R&D environment.
Ready to Apply?
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