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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.

CALL 0800 195 6468 Schedule Appointment

NO CALL-OUT FEE

Pay only for breakdown & repair time.

SAME DAY REPAIR

We operate 24/7 across Greater London.

FULL WARRANTY

12 Months on parts replacement.

Diagnosis & Solutions

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.

Transparent Process

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

Repair Rates

HIU Breakdown & Repair Rates

Monday to Friday

8am to 5pm

£150+VAT

Per hour (1 hour minimum charge)

Congestion charge included
No driving charge
No parking charge
Full report with photos

POPULAR

R&B Returning Customers

Forever 20% Discount

£125+VAT