When an under sink water heater begins to leak, prompt action is essential to prevent water damage, electrical risk, and disruption to hot water supply.
Fix & Repair Engineers recently completed the replacement of a faulty Ariston instantaneous under sink hot water heater at a property in West Ealing, London, restoring safe and reliable hot water provision.
Project Overview
- Location: West Ealing, London
- Equipment: Ariston instantaneous under sink water heater
- Issue Reported: Internal leak and component failure after approximately six years of service
- Outcome: Full unit replacement, safe decommissioning, installation and commissioning of new heater
The original unit had developed internal leakage. Upon inspection, it became clear that the cost of required replacement components and labour would exceed the practical value of repair. In line with best practice and cost efficiency for the client, replacement was recommended.
What Was the Problem?
Instantaneous under sink water heaters are compact, high-performance units designed to deliver hot water on demand. Over time, common issues can develop, including:
- Internal tank or heat exchanger corrosion
- Seal and connection degradation
- Electrical component failure
- Pressure-related leaks
- Thermostat or heating element malfunction
In this case, the existing Ariston unit had begun leaking internally after six years of operation. The leak posed both water damage and electrical safety risks.
Given the age of the appliance and parts required, replacement was the most economical and technically sound solution.
Decommissioning the Faulty Unit
Safe removal of instantaneous electric water heaters requires careful isolation of:
- Electrical supply
- Cold water feed
- Hot water outlet connections
Our engineers:
- Fully isolated the electrical circuit
- Shut off and drained the water supply
- Safely disconnected pipework
- Removed and disposed of the faulty heater in accordance with waste regulations
This ensured no risk remained before installing the replacement unit.
Installation of the New Ariston Instantaneous Water Heater
A new Ariston instantaneous under sink heater was supplied and installed. Installation included:
- Secure mounting within the under sink cupboard
- Reconnection to existing pipework
- Verification of inlet pressure compatibility
- Electrical reconnection in accordance with UK wiring regulations
- Seal integrity checks
Correct sizing and compatibility checks were carried out to ensure the new unit met demand requirements and operated within manufacturer specifications.
Commissioning & Operational Testing
Following installation, the unit was fully commissioned. This included:
- Electrical safety verification
- Live operational heating test
- Flow rate assessment
- Temperature stability check
- Leak inspection under pressure
- Final compliance checks
The heater was tested for complete and correct operation, ensuring:
- Rapid hot water delivery
- Stable output temperature
- No leakage
- Safe electrical function
The client’s hot water supply was restored immediately following commissioning.
Why Replacement Was the Correct Decision
In many cases, under sink water heaters approaching or exceeding 5–7 years of service life may develop multiple component failures simultaneously. When:
- Repair parts are costly
- Labour time is significant
- Efficiency has declined
- Warranty has expired
Replacement is often the most economical and risk-mitigated approach.
A new unit provides:
- Improved energy efficiency
- Manufacturer warranty protection
- Reduced risk of future leaks
- Reliable performance
Common Signs Your Under Sink Water Heater May Need Replacement
If you manage a property or commercial premises in London or the Home Counties, look out for:
- Visible leakage beneath the unit
- Tripping electrical circuits
- Inconsistent water temperature
- Reduced hot water output
- Rust staining around fittings
- Unusual noises during heating
Early intervention prevents secondary damage to cabinetry, flooring, and electrical systems.
Local Service – London & Surrounding Areas
Fix & Repair Engineers provide professional water heater repair and replacement services across:
- West Ealing
- Ealing
- Kensington
- Central London
- Greater London and the Home Counties
Our engineers are qualified, experienced, and compliance-aware, ensuring all work is carried out safely and to UK standards.
Need a Water Heater Replacement in London?
If your under sink hot water heater is leaking, inefficient, or no longer reliable:
- Request a quote
- Arrange an inspection
- Book a replacement
- Call for urgent assistance
Provide the make and model (if known), location of installation, and symptoms observed to allow rapid diagnosis.
Fix & Repair Engineers deliver professional, compliant and dependable installation and replacement services across London.
With many years on the tools in all aspects of the engineering industry has given me a second to none skill set which enables me to provide a leading professional service to my customers with a wealth of knowledge and highly skilled engineers to successfully cover all your plumbing, heating, AC and catering equipment requirements.
