DIY SOS – from pest infestations to mold and electrical failures, there are the 9 times you should always call a pro

When it comes to home maintenance, saving money on the fix is often a high priority. From hanging shelves, sorting plumbing issues and even redecorating, there are a myriad tasks around the home which can be dealt with yourself.

But there are also times when expert help is not only necessary, but the sooner you call in the pros, the better.

Here, I spoke to our panel of home experts for their tips on the nine problems and projects you should leave to a pro.

How to know when it's time to call the pros

1. Serious mold issues

If you identify any of the common types of household mold in your home, and your attempts to clean mold off walls or get rid of black mold fail, it's crucial to call in the pros.

This is especially relevant where the surface area of the mold is large.

Karina Toner, cleaning expert and operations manager at Spekless warns, 'Mold can spread quickly and pose serious health risks, such as respiratory issues or allergic reactions. DIY treatments often miss spores hidden in walls or under surfaces, allowing the mold to regrow. Professionals can assess the extent of the problem and safely remove all traces using specialized equipment.'

Really, as Toner advises, you should call the pros at the very first sign of mold, which may be discoloration or wondering why your house smells musty, and particularly if the mold covers an area larger than 10 square feet, or, importantly, recurs after cleaning.

Additionally, a lesser-known cause of serious mold issues is vinyl flooring, says Evie Graham, professional cleaner and founder of Waste Direct, even if you know how to clean vinyl floors properly.

She explains, 'Most cleaning guides won't tell you this but luxury vinyl flooring has become a silent harbinger of serious mold issues. Through my professional experience, I've discovered that the waterproof nature of luxury vinyl actually masks underlying moisture problems.

'When clients attempt DIY cleaning of what appears to be surface mold, they often miss the extensive colonization happening beneath. Call professionals immediately if you spot even minimal discoloration on vinyl flooring – this isn't a surface issue you can tackle with household cleaners.'

Then, once cleared, it may be worth investing in one of the best dehumidifiers to keep humidity – and mold – at bay.

All prices were correct at time of publication.

2. Electrical failures

While it's possible to fix loose outlets or change a lightbulb above the stairs, when it comes to electrical failures, always leave it to the experts to avoid risk of electrocution or fire.

Al Fagundes, founder of A. Fagundes Plumbing & Heating Inc. says, 'Messing with electrical components without proper training can cause shocks, fires, or permanent system damage. These are issues to address immediately, as delays can escalate the risk and repair costs.'

For example, if you encounter any common thermostat problems, your HVAC system isn't powering on, or you notice flickering lights when the unit runs, 'it's time to step back,' advises Fagundes.

3. Refrigerant leaks

While refrigerant leaks may be one of the reasons your AC unit freezes up, fixing it should always be left to professionals.

Josh Mitchell, HVAC technician and founder of AirConditionerLab, says, 'Dealing with refrigerants isn't just about skill – it's about legality. Due to their potential environmental impact, handling refrigerants requires certification under EPA regulations. Refrigerant leaks can also be a sign of bigger problems with the system.'

Therefore, it's imperative to call an expert immediately upon suspicion or detection of a leak, whether your air conditioner is leaking water or your AC vents are dripping water.

'Delaying could lead to higher operational costs and system failure,' adds Mitchell.

4. Severe pest infestations

One of the unfortunate constants in life is having to deal with pests, and while a few ants or flies may be manageable, getting rid of termites, bed bugs or dealing with common winter pest infestations may be a different story.

As professional cleaner Toner says, 'Pests can cause structural damage, spread disease, and are difficult to eliminate without proper training and tools.'

So, either call the pros immediately after identifying any indoor pests, or seeing signs of one including droppings, teeth marks, nests. If you have tried some DIY methods, such as using baking soda to kill ants or getting rid of moths with vinegar and the pests have come back, or you are feeling stressed and overwhelmed, it's time to call in the pros.

It's important to note that 'waiting too long can lead to significant damage or increased costs,' warns Toner.

5. Grease clogs

While it is possible to fix a clogged kitchen sink, if grease is one of the reasons why your sink won't drain, it's best to call in a professional plumber.

Cleaning expert Graham says, 'Crytallized grease blockages in modern drainage systems are virtually impossible to clear without professional intervention. These aren't your standard clogs,' which can be cleared with products such as the number one bestselling Drano Max Gel Drain Clog Remover and Cleaner for Shower or Sink Drains available at Amazon.

'When cooking oils combine with biodegradable detergents (especially eco-friendly ones) they create rock-hard crystalline structures that bond chemically with pipes,' continues Graham.

'I've seen countless cases where DIY drain cleaning solutions actually accelerated pipe deterioration. The moment your drain starts gurgling or draining slowing – especially if you use eco-friendly products – call a professional.

'Those initial symptoms indicate crystallization has begun, and every DIY attempt only compounds the problem,' specifically when dealing with grease and fat blockages.

6. A faulty furnace or boiler

Much like electrical failures, a faulty furnace or boiler that leaves you wondering why your house is so cold even with heating should be fixed by an expert.

As Robert Hamerly, principal at GreenSavers, says, 'If your furnace or boiler seems faulty, you'll want to get a professional to handle it as quickly as possible. These types of machines function via pressurization and combustion, which should be daunting enough to give any DIY-er pause.

'Call someone in to fix up your system, or better yet, consider replacing a faulty furnace or boiler with a fully electric heat pump or heat pump water heater to increase efficiency and sustainability overall.'

If you're wondering how long a furnace lasts, the average lifespan is between ten and twenty years, but this will depend on usage, model, and the size of the home it is used to heat.

'And yes, you will definitely want to call a professional to do that installation process,' adds Hamerly.

7. Any issue that simple HVAC maintenance won't fix

Aside from refrigerant leaks, Max Veggeberg, CEO and founder of Tetra, says, 'Homeowners should start with simple maintenance like replacing air filters, and ensuring vents are unblocked. Address drafts by sealing windows and doors (with caulk, such as the GE Advanced Silicone Caulk for Kitchen & Bathroom available at Amazon) and adding insulation in key areas.

'If these steps don't solve issues like temperature changes, cold spots, or inefficiencies – or if you notice strange odors, unusual noises, or need help with duct work, refrigerant, or electrical repairs – it's time to call a professional.'

This is because all of these issues require specialized training and tools, and therefore should be left to licensed, trained professionals. 'Improper repairs can lead to safety risks, such as electrical hazards or compromised air quality, and can also reduce system, efficiency, increase bills, or cause further damage.'

You should also endeavor to have your HVAC system serviced at least once annually, and ideally twice.

8. Extensive water damage

Water damage is one of the most devastating home disasters, which is why it's important to get it dealt with quickly, efficiently, and, most importantly – professionally, whether you need to get water out of a carpet after a flood, or fix a ceiling with water damage.

Professional cleaner Toner says, 'Water damage can lead to structural issues and mold growth if not addressed correctly. Professionals use moisture meters and industrial-grade dryers to thoroughly mitigate damage.'

So, as soon as you notice any signs of water damage, such as soaked carpets, sagging ceilings, or warped walls, call in the pros. In the meantime, it will be useful to know how to dry waterlogged items to minimize damage to your belongings.

9. Carbon monoxide issues

Finally, unlike smells that could be a sign of danger in your home, carbon monoxide is odorless and virtually undetectable – which is why it's so important to install carbon monoxide alarms and call an expert if you suspect any issue at all around your home that may be causing a carbon monoxide leak.

Simon Bernath, CEO and founder of FurnacePrices.ca says, 'If there is anything that suggests an issue, like a cracked heat exchanger or any other issue which could be causing a carbon monoxide leak for instance, that is something that should be dealt with by a professional immediately.

'So, make sure you have working detectors installed, and test them at the start of the heating season to make sure they're working. And don't ignore it if it's going off but the furnace or heating system otherwise seems to be working OK.'

Also, don't forget to test your smoke detector, either, if you don't have a combined alarm model.

Wondering whether you should hire a handyman? Most of the time, if you're considering it, the answer is yes. Next, delve into the household projects not to DIY.