Frequently Asked Questions
Answers to the questions we're asked most about air conditioning, boilers, servicing, landlords and more. Can't find what you're after? Get in touch and we'll help directly.
How much does air conditioning installation cost?
Cost depends on the size of the space, the number of rooms, and the system you choose. We offer a free, no-obligation home survey so we can give you an accurate, fixed-price quote tailored to your property.
Do you install air conditioning in both homes and businesses?
Yes, we install residential and commercial air conditioning systems across London, Kent, Essex, Sussex and the South East, from single-room units to full multi-room and commercial setups. See our air conditioning and commercial air conditioning pages.
How long does an air conditioning installation take?
Most single-room installations are completed in a single day. Multi-room or commercial systems can take longer depending on the number of units and property access.
Which air conditioning brands do you install?
We install and service leading brands including Panasonic, Daikin, Mitsubishi Electric, Samsung and Bosch.
Do air conditioning installations come with a warranty?
Yes, every installation includes the manufacturer's warranty, registered on your behalf as part of the installation process.
Can you install air conditioning in more than one room?
Yes, multi-split systems allow several indoor units to run from a single outdoor unit, ideal for cooling multiple rooms without needing separate outdoor units for each.
Can air conditioning also be used for heating?
Yes, most modern air conditioning systems work as reverse-cycle heat pumps, providing efficient heating in winter as well as cooling in summer.
Is air conditioning noisy?
Modern indoor units are designed to run quietly, and outdoor units are positioned to minimise noise. If a unit becomes unusually loud, that's usually a sign it needs a check.
Can I control my air conditioning from my phone?
Yes, most systems we install include Wi-Fi connectivity and app control, so you can adjust settings remotely.
Where does the outdoor unit need to go?
Typically on an exterior wall, ground mount, or roof space with good airflow. We assess the best position for your property during the free survey.
Do I need planning permission for air conditioning?
Most residential installations don't need planning permission, though listed buildings or certain flats may have restrictions. We can advise during your survey.
Can you install air conditioning in a garden room or outbuilding?
Yes, we regularly install air conditioning in garden rooms, home gyms, and converted outbuildings, provided there's suitable electrical supply and outdoor unit access.
Why is my air conditioning not cooling properly?
This can be caused by low refrigerant, a blocked filter, or an airflow issue. Our engineers can diagnose the cause and carry out the repair. See our repair guide for more.
Why is my air conditioning unit leaking water?
This is usually a blocked condensate drain. It's a common, fixable issue, worth getting checked promptly to avoid water damage.
What does F-Gas qualified mean?
F-Gas registration is the legal qualification required to handle refrigerants used in air conditioning systems. All our engineers hold this qualification.
How do I know what size boiler I need?
Boiler size depends on your property's heat loss, number of bathrooms, and hot water demand. We carry out a proper assessment on every quote so you're not guessing on size.
Should I repair or replace my boiler?
It depends on the boiler's age, the cost and frequency of repairs, and its efficiency. Our repair or replace guide walks through how to make that call.
What's the difference between a combi and system boiler?
A combi heats water on demand with no tank, suited to smaller homes. A system boiler uses a hot water cylinder and suits larger homes with more than one bathroom.
What do I do if my boiler breaks down?
Call us directly and we'll get an engineer out as quickly as possible. See our boiler breakdowns page for more information.
Why does my boiler pressure keep dropping?
This is often caused by a small leak in the system or a faulty valve. If it happens repeatedly, it's worth having an engineer investigate rather than just topping up each time.
Why is my boiler making a strange noise?
Different sounds point to different causes, from trapped air to limescale build-up. It's worth having it checked rather than ignored, as some noises indicate a developing fault.
What warranty comes with a new boiler?
Warranties vary by manufacturer and model, often up to 12 years for premium brands like Worcester Bosch and Vaillant when installed by an accredited engineer, which we are.
How long does a boiler typically last?
Most boilers last 10-15 years with regular servicing. See our boiler lifespan guide for tips on getting the most out of yours.
What is a power flush and do I need one?
A power flush clears sludge and debris from your central heating system, often recommended if radiators have cold spots or the system is underperforming. See our power flushing page.
Why is my radiator not heating up properly?
This is usually trapped air, a stuck valve, or sludge build-up, depending on the pattern of cold spots. See our radiator troubleshooting guide for the full breakdown.
Can you convert my old back boiler to a combi?
Yes, we carry out back boiler to combi conversions, though this is a more involved job than a like-for-like swap due to the extra pipework and removal work involved.
Are your engineers Gas Safe registered?
Yes, every boiler and gas job is carried out directly by our own Gas Safe registered engineers, registration number 670242.
How often should air conditioning be serviced?
Once a year is recommended for most residential systems, ideally before the summer season when the unit works hardest. See our air conditioning servicing page for details.
Why does my boiler need an annual service?
An annual service catches small issues before they become breakdowns, keeps the boiler running efficiently, and is usually required to keep manufacturer warranties valid. See our boiler servicing guide.
Do you repair or service systems you didn't install?
Yes, our F-Gas and Gas Safe engineers repair and service all major makes and models regardless of who carried out the original installation.
What happens if I skip a service?
Performance and efficiency gradually decline, running costs increase, and small issues can develop into more expensive repairs. Most manufacturer warranties also require proof of regular servicing.
Do I get proof of service for my records?
Yes, we provide a written service report after every visit, useful for warranty claims, landlord records, or your own peace of mind.
Do I need a landlord gas safety certificate?
Yes, it's a legal requirement for any rental property with gas appliances, renewed every 12 months. See our landlord gas safety guide for full details.
Do I need to give tenants a copy of the certificate?
Yes, you're required to provide a copy within 28 days of the check, or before a new tenancy begins.
What happens if my gas safety certificate lapses?
Letting it expire is a criminal offence, with potential fines and prosecution, and it can also invalidate landlord insurance. It's important not to let this lapse.
Do I need a certificate if my rental has no gas appliances?
No, if there's genuinely no gas supply or appliances in the property, a certificate isn't required. If there's any gas connection at all, it applies.
Can you combine a gas safety check with a boiler service?
Yes, many landlords book both together in a single visit, which is more convenient and cost-effective than two separate appointments.
How long do I need to keep gas safety records?
You're required to keep gas safety records for at least two years.
Do you install EV chargers?
Yes, our electrical team installs EV home chargers as part of our wider electrical services.
Are your electricians NICEIC approved?
Yes, our electrical work is carried out by NICEIC approved electricians.
How long does an EV charger installation take?
Most home EV charger installations are completed within a few hours, depending on your property's electrical setup and where the charger is being fitted.
What other electrical work do you cover?
Alongside EV chargers, our electrical team covers a range of general electrical work. Get in touch to discuss your specific requirements.
Are your engineers qualified to work on gas and air conditioning systems?
Yes, all gas work is carried out directly by our own Gas Safe registered engineers, and all air conditioning work by our own F-Gas qualified team, not subcontracted out.
Do you offer free quotes?
Yes, every job starts with a free, no-obligation survey and a clear, fixed-price quote before any work begins.
What areas do you cover?
We cover Dartford, Bexleyheath, Gravesend, Sevenoaks, Maidstone, and across Kent, Essex, Sussex, London and the South East.
How long has Smart Plus Heating been operating?
The leadership team brings over 80 years of combined experience in the heating and electrical industry. Find out more on our about us page.
What accreditations do you hold?
We're Gas Safe and F-Gas registered, a British Gas partner, Which? Trusted Trader, Worcester Bosch and Vaillant accredited, and hold reviews on Checkatrade, Trustpilot and Google.
What payment methods do you accept?
Get in touch with our team directly and we'll confirm the payment options available for your job.
Are you fully insured?
Yes, we are fully insured for all the work we carry out.
How do I book a job or get in touch?
Call us on 01322 474 990, message us on WhatsApp, or use the contact form and we'll get back to you within 24 hours.
What are your opening hours?
Our standard hours are Monday to Friday, 8:00 AM to 6:00 PM. Contact us directly for emergency boiler breakdown availability.
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