No Hot Water Or Heating?
Expert HIU Repair
Many standard plumbers and gas engineers frequently misdiagnose HIU faults, often blaming everything on a blocked plate heat exchanger. Sound familiar? At R&B London HIU Engineers, we specialise exclusively in HIU diagnostics and repairs. Our engineers carry fully stocked vans with the most common parts for Evinox, Danfoss, Caleffi and other major HIU brands allowing many repairs to be completed on the first visit.
We provide fixed-price repairs, expert fault diagnosis, and all repair works come with a 12-month warranty for peace of mind. Our company is also fully insured with £5 million public liability cover.
Common HIU Faults
No Hot Water
Blocked strainer, faulty actuators, sensors, or a blocked plate heat exchanger are common causes. Our HIU specialists carry diagnostic tools and common replacement parts to identify the fault and restore hot water as quickly as possible.
Cold Radiators
Usually caused by stuck control valves, circulation pump issues, or restricted flow. Our engineers diagnose the heating circuit and replace faulty components where required.
HIU Leaking
Leaks can occur due to worn seals, PRV discharge, or internal component failure. We locate the source of the leak and repair or replace the affected parts before pressure testing the unit.
Noisy HIU
Often caused by air in the system, low pressure or crossed flow. We inspect internal components, clean filters, and correct flow restrictions to reduce noise.
How Our HIU Repair Service Works
Transparent diagnosis, fixed-price repairs, and no work carried out without customer approval.
Expert Diagnosis
Our engineer first checks whether the issue comes from the communal heating system before inspecting the HIU itself. Once confirmed within the unit, we carry out a full diagnosis to identify the exact cause of the fault.
Fixed Price Repair
If the issue can be repaired during the visit, our engineer will fix it on the spot. When replacement parts are required, we confirm the cost with the customer before fitting any components.
Report & Follow-Up
You receive a detailed PDF report with photos of the work carried out. If a required part is not available in our vans, we provide a fixed-price quote to supply and install it.
What Our Customers Say About Our HIU Repairs
HIU Breakdown & Repair Rates
Monday to Friday
8am to 5pm
Per hour (1 hour minimum charge)
- Congestion charge included
- No driving charge
- No parking charge
- Full report with photos
R&B Returning Customers
Forever 20% Discount
Per hour (1 hour minimum charge)
- 8am to 5pm Mon - Fri
- Congestion charge included
- No driving charge
- No parking charge
- Full report with photos
Out Of Hours
Emergency 24/7
Fixed price for 1st appointment
- 5pm to 7am any day
- 24h Weekends & Bank Holidays
- Congestion charge included
- No driving/parking charge
- Full report with photos
Book Your Specialist
Same-day emergency response across all London postcodes.