I deal with hundreds of cases a year from homeowners where a dehumidifier is running but not impacting the humidity levels. There are a few reasons why this can happen, but I find with older models that, it’s usually a sign that the dehumidifier needs to be recharged.
I’ve worked in the HVAC industry for over a decade, and the laws and regulations are constantly changing – including the rules around who is actually allowed to recharge dehumidifiers.
In this guide, I’ll explain what recharging your dehumidifier means, how and when you should recharge it, and whether you can do it yourself or if you have to hire a professional.
How to Recharge a Dehumidifier
Recharging a dehumidifier isn’t straightforward and often requires a professional to do it for you. It is technically possible to do it yourself, but in most areas, there are laws stating that only certified professionals can do it.
I would recommend checking your local codes or contacting your local council to check before you proceed.
- A dehumidifier recharging kit. These recharging kits will usually contain a gas cylinder of coolant/refrigerant which can be used to recharge the device. Most modern units use R-410A refrigerant but older units use R-22 refrigerant. Check the user manual to find the right one.
- Screwdrivers and wrenches
- Towels (to catch any water from the device)
You can pick up everything you need online or at your local hardware store.
Recharging Refrigerant Dehumidifier
- Run the dehumidifier; (this step is optional as you can recharge it without turning it on)
- Remove the valve cover
- Connect the filler line to the exposed valve, don’t open it yet
- Let out all the excess air from the filler’s pipe so that there aren’t any damages to the valve or the compressor
- Connect the valve with the filler and make sure the connection is fit.
- Now open the valve and check whether the coolant is there or not.
- Start refilling in short bursts.
- Watch the pressure gauge level and stop filling when the level reaches sufficient height.
- Close the valve and remove the filler’s pipe
Recharging Desiccant Dehumidifiers
A desiccant dehumidifier works using a material that absorbs moisture from the air. They work best in smaller, enclosed spaces and I have desiccants in my car, office, and bedroom.
Desiccant dehumidifiers don’t need to be recharged in the same way because they don’t have internal coils or refrigerant. Instead, they just need to be dried out so the absorbent material can start working again.
Silica gel or silica beads are used in a lot of desiccant dehumidifiers. This can be dried out and reused in a number of ways:
- If you have an electric silica desiccant dehumidifier then it will likely be able to dry itself out. Plug in the dehumidifier, wait for the silica beads to heat up and dry out, and then use it again.
- If you’re using a non-electric desiccant dehumidifier you should remove the material (silica, charcoal, salt etc.) to dry it out. Silica packets can usually be microwaved, whereas other materials can be left in the sun to dry.
- Certain materials can’t be reused. If they have absorbed all the moisture they can then you’ll need to throw them away and replace them.
Safety Precautions When Recharging a Dehumidifier
I would always recommend getting professional help to recharge your dehumidifier. It’s a job that even I find complicated, but it’s also a legal requirement in many countries that you have to be a certified technician to attempt it.
However, if you are determined to do it yourself, and it’s legal to do so, then you should take the following precautions:
Keep away from children – coolants are dangerous gases, and they can cause severe harm. Therefore, you must keep your children far from dehumidifiers when recharging them.
Recharge in a well-ventilated place – refrigerant is hazardous so you should perform the recharge in a place with plenty of fresh air. This will help to stop you from breathing in any dangerous chemicals.
Wear a facemask – it’s also a good idea to wear a facemask to protect yourself from harmful chemicals. I always use a complete face covering to be as safe as possible.
Use a heat-resistant surface – dehumidifiers can give off a lot of heat when it’s recharging. Lay it on a heat-resistant surface to prevent any damage to your home, and keep it open until it starts to cool down again.
When to Recharge a Dehumidifier?
A dehumidifier shouldn’t need to be recharged and if there’s no damage to the unit then the refrigerant levels won’t deplete. However, if you notice any of the following then it’s a sign that your refrigerant is running low and you need to recharge your device:
- Light indicator on the control panel – many modern dehumidifiers will have a specific display to tell you it needs to be recharged. I don’t often see this feature but it is useful on newer models.
- Dehumidifier running constantly – if the refrigerant levels are low your dehumidifier will have to run more frequently to decrease humidity in your home.
- Too much moisture in the air – if your dehumidifier is running but the humidity isn’t decreasing then it’s a sign that it isn’t working properly and needs to be recharged.
- Empty water tank – if water isn’t gathering then it means the moisture levels aren’t coming down. This is usually because the condensate dehumidifier evaporator coils need to be recharged.
- No dry air – if the air blowing from your dehumidifier isn’t dry then the moisture isn’t being collected on the condenser coils. This is usually a sign that it needs to be recharged.
If you notice any of the above then the safest option is to call a reliable HVAC agency to take a look at the dehumidifier, especially if you have an expensive whole-house model.
Remember, recharging your device is expensive and won’t solve the underlying issue of refrigerant leaking. If you’re having to recharge your dehumidifier frequently you’ll need to consult a professional to establish the root cause of the issue.
DIY Recharging vs Hiring an HVAC Professional
I always look for DIY solutions, but recharging a dehumidifier is a challenging task and there are pros and cons to hiring a professional:
Advantages of hiring a professional:
- You won’t break local guidelines or laws – There are a lot of strict environmental regulations which need to be followed when you’re handling coolant and I would recommend checking all local laws and guidance thoroughly before you proceed. They need to be handled and disposed of in the right way and a professional will know exactly what to do so no guidelines or laws are breached.
- It’s safer – Dehumidifier coolants produce chemicals that have ozone depletion potential. This basically means that they are dangerous chemicals and need to be handled very carefully, which is why it’s often safer to hire a professional to recharge your dehumidifier.
Advantages of DIY recharging:
- It’s cheaper – most repair services will charge $100-$500 to recharge your dehumidifier, depending on the size, make, and model. If you do it yourself you’ll only need to spend $50 on a recharge kit so you can make a significant saving.
- No waiting – it can take time to book an HVAC company to come and recharge your dehumidifier, but in the meantime, your home will have no defense against the humidity. If you do the task yourself then you control the timescales.
If you have some experience with DIY and handling substances like refrigerant then you can potentially get away with recharging it yourself by following this guide or YouTube videos.
However, hiring a professional is the safer and less stressful option with much less risk of damaging your dehumidifier, and I’d definitely recommend hiring a professional if you have a larger whole-house dehumidifier.
What Kind of Dehumidifier Needs Recharging?
Technically, recharging a dehumidifier is where you top up the refrigerant in the device, and therefore only dehumidifiers that use refrigerant need to be recharged.
I use a desiccant dehumidifier in my office and while it does need to be dried out periodically to be ‘recharged’ it’s a very different (and much simpler) process.
So, why do refrigerant dehumidifiers need to be recharged? It all comes down to how they operate.
Refrigerant dehumidifiers are the most common type of dehumidifier and they are what I use 90% of the time. They work using condenser coils which are filled with refrigerant that keeps them at a cold temperature.
As humid air is drawn in, the excess moisture in the air condenses on the coils and is collected within the water tank. The dry air is then released into the home.
Over time, the refrigerant levels within the appliance will drop. This can be due to tiny cracks or damage within the device which causes a refrigerant leak.
If there isn’t enough refrigerant then the dehumidifier won’t be able to absorb moisture and you’ll be left with a damp environment.
Having your dehumidifier recharged periodically will stop this from happening and allow your dehumidifier to prevent high humidity in your home.
Can Every Refrigerant Dehumidifier Be Recharged?
It is possible to add refrigerant or coolant to every refrigerant dehumidifier but it can be a lot more difficult with modern models. How simply it can be done will depend on your specific dehumidifier model.
Older dehumidifiers are generally easier to recharge. You can buy dehumidifier recharge kits and top up the dehumidifier quickly yourself, allowing the dehumidifier to regulate the moist air more quickly.
However, not all dehumidifiers are easy to recharge. Over time, the hazards and dangers of refrigerant have become more well-known, and stricter guidelines about handling coolant responsibly have been introduced.
It’s now more difficult to access the machine’s control panel and internal compressor to discourage people from tampering with the cold coils themselves.
This makes it a more challenging task and while I love new, efficient dehumidifiers, I’m not always a fan of their design.
It is possible to recharge stand-alone dehumidifiers or portable dehumidifiers, but with most modern dehumidifiers, you will need to hire a professional to do it for you.
This isn’t just because I think it’s too hard for non-professionals, it’s actually the law in many states and countries that only certified HVAC technicians can recharge them.
How can you avoid recharging your dehumidifier?
The best way to avoid having to recharge your dehumidifier, you should take good care of it. This involves regularly cleaning and emptying the water tray, letting it rest, and closing windows when it functions.
What happens if recharging doesn’t work?
Dehumidifiers are the most commonly overworked appliance in American households, and sometimes recharging it may not work. Unfortunately, this means that it either needs a new compressor or needs to be replaced entirely.
I have a lot of experience with dehumidifiers and even I think recharging modern models can be tricky.
I would always recommend hiring a professional to do the work because it’s safer, and stress-free. It could also end up being cheaper than having to pay for repairs because you’ve tried it yourself and something has gone wrong.
However, if you are feeling adventurous, then hopefully this guide will help you do it yourself. Just make sure you check all the local laws and regulations before you start.