RV Water Pumps Can Freeze! Here Is How To Fix & Avoid It

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Some RV owners retire their vehicles as winter approaches, while others (such as myself) stick it out all year. In both scenarios, your motorhome’s water pump may be exposed to colder-than-usual conditions. Can the water pump end up frozen?

Your RV water pump can freeze, as can all water system components, including the holding tanks and the freshwater lines. If your water pump is frozen, you’ll have to thaw it using a heating element. 

In this article, I’ll talk more about how likely it is for your water pump to freeze, why it happens, how to thaw a frozen pump, and how to prevent it. After all, of all the components of your caravan’s water system that can freeze, the water pump can often be the costliest! 

Is It Possible for an RV Water Pump to Freeze?

Your motorhome’s water pump controls the water pressure so that when you’re camping out, you get a reliable flow of water for showering, cooking, cleaning, and drinking.

As I mentioned in the intro, the pump is a part of a more extensive system known as your water system with freshwater lines and holding tanks. All parts of the water system can freeze, including your water pump.

What causes a frozen pump? That’s simple – cold temperatures! 

Many RVers retire their motorhomes, caravans, or RVs around the beginning of winter or late autumn and don’t see them again until the warm spring or summer days arrive.

If you pay for your motorhome to sit in an indoor storage facility with temperature control, your water pump won’t freeze.

However, this is expensive to do. After all the winterization and maintenance you just put into your RV to end the season, paying for high-end storage might be the last thing on your list. 

Indoor storage without temperature control is better than outdoor storage, but not by much. Your water pump could still freeze. That’s the likeliest outcome if you store your motorhome outdoors for months during the coldest time of the year. An uninsulated cover won’t protect your pump enough. 

What about those of us who never retire our RVs? Whether your water pump is at risk of freezing depends on where you go. 

If you’re like the birds that flock to warmer climes for the winter, then camping out in a place with milder temperatures shouldn’t risk your water pump. For those who like to brave the winter chill, leaving your RV exposed to the elements puts the pump in danger.

I should note that it’s not only your water pump that’s at risk. There’s the whole motorhome water system, as I mentioned, as well as other components of your RV. 

Water pumps can have a lot go wrong with them as it is. You might recall this article where I talked about whether or not you should turn off your water pump at night since some pumps start automatically when the pressure in the water pipes drops, and if you have a leak, that’s gonna be problematic.

When comparing all the parts of your motorhome, RV, or caravan’s water system, the pump can be somewhat costly to replace. You can spend upwards of $500 on a new pump.

Of course, there are cheap ones as well but my original Fiamma water pump has from what I can tell worked for 28 years now so it could be worth it to buy high-end parts.

Save yourself money and do what you can to prevent the pump from freezing. An ounce of prevention is worth a pound of cure! 

How Do I Know If My RV Water Pump Froze?

Are your taps supposed to be working fine, but no water is coming out? Or maybe the water is coming out, but it’s moving ultra-sluggishly? Both are signs that part of your motorhome water system has frozen. 

If the freshwater tank froze, then chances are pretty good that the pump has as well. The reason? The water pump is only about two feet away from the tank, maybe three feet at most.

Try opening either tank to confirm that your greywater or blackwater tanks are solid masses. Nothing will emerge when you do. 

It doesn’t necessarily take the entire tank to freeze for operability to decrease, by the way. If even the discharge valve freezes, then the tanks can stop working.

However, if only the discharge valve has frozen, that doesn’t necessarily mean your RV water pump has. It doesn’t bode well, though! 

How Do You Fix a Frozen RV Water Pump?

Alright, so you’ve deduced that your RV water pump is frozen. This is dismaying news considering the cost of replacing the pump is high. Don’t panic quite yet. You might not necessarily have to replace the pump when you can thaw it first. Here are the measures at your disposal.

All of which should start by cranking up your furnace/heater inside your RV, and this alone can, in many cases, solve your problem it will take a while, but if your motorhome, caravan, or RV is made for winter use, this is in most cases sufficient.

Since the original RV heater usually runs on either propane, diesel, or sometimes electricity is evenly spreading out the heat throughout your RV with “heat pipes” to different ventilations/outlets around your RV.

Those heat pipes usually go next to the water pipes, holding tanks, and water pump to keep those from freezing. Hence, it’s essential to use the original heating system compared to an external space heater. And this is, therefore, in most cases sufficient to start your heater and increase the heat for a couple of hours.

But if you don’t have that type of setup or if that is not sufficient, you should start with some of the following options;

Propane Heater / Space Heater

Since a frozen water pump is often accompanied by a frozen greywater and/or blackwater tank, the fastest way to thaw one component of your motorhome’s water system is to thaw them all.

You can use a propane or space heater to deliver large blasts of heat. All you have to do is put the heater under your RV. Aim the heater towards the holding tanks to direct a targeted burst of hot air.

Combine this with an RV skirt or put insulation/something to cover the open sides underneath your RV, and you will get a heated area underneath your RV. This will also help increase the temperatures inside your RV quicker, where you run your original furnace/heater to thaw the rest of the water system.

It might take a few minutes, but the tanks, water pump, and the whole water system will thaw. You can now drain those overfull greywater and blackwater tanks and enjoy running water again.

Some winter campers use this technique with a space heater and RV skirts or insulation or even by using snow to cover up the sides around their RV to get a heated area underneath the RV if they don’t have a motorhome well insulated for winter use and this way you get heated floors as well!

Be aware not to cover up the ventilation holes if you do this!

Well, it should be that easy, but it isn’t always. If you use a propane heater for too long or too close to certain parts of your RV, there does exist the risk that those components can catch on fire. They can also melt, which isn’t as bad but still not great. 

Then, of course, there’s also the risk of carbon monoxide exposure if you hang out underneath the RV at this stage or if all the ventilations are covered, and you are inside. Installing a carbon monoxide detector is always a good idea!

Oh, and don’t leave the propane heater unattended! 

Heating Blanket

A heating blanket is an ideal tool to keep on your caravan, especially a big one that produces a high heat output. You can drape the blanket over the frozen water pump; sooner than later, it should thaw.

Hairdryer

Okay, so we’re admittedly getting into the less glamorous options. 

I’m sure you have a hairdryer in your RV for after your shower. Find an outdoor outlet, plug the hairdryer in, and turn it up to its highest heat setting. Hold the hairdryer over your water pump, focusing the heat blast first at the top, then at the sides, and then underneath.

Although tempting, don’t put the hairdryer too close to the heat pump. Also, listen to your dryer for signs that it’s straining. 

When a hairdryer catches on fire, it’s scary stuff!

This option is incredibly time-consuming. I can’t tell you how long it will take because that depends on the heating capacity of your hairdryer and the size of your water pump, and how frozen it is.

Do expect to be at it for a while, though! But combining this with running the furnace/heater in the RV will speed up the process, and it is excellent when one part of the water system is frozen.

If it’s cold enough for your motorhome, RV, or caravan water pump to freeze, then the thought of standing outside with your hairdryer for upwards of an hour or maybe longer might not be that appealing if the access to your water pump is from the outside.

I can’t blame you for that at all. Fortunately, you have one more option to consider.

Heat Gun

A good heat gun won’t set you back more than $30, and an excellent one costs under $150. 

Although you won’t find many uses for a heat gun around your RV, when the parts of your water system freeze, the heat gun is a godsend. A heat gun can thaw pipes, tanks, and your water pump in no time; it could also help you out with other tasks such as removing old sealants, eternabond tape, or adhesives.

Using the heat gun, you’d follow the same instructions as thawing with your hairdryer.

Plug it in, hold it a decent distance from the frozen water pump, and keep blasting that concentrated heat until the area is thawed. Then move on to the next.

Unlike a hairdryer, a heat gun produces a much more concentrated blast of hot air so that you will thaw your water pump faster. That said, this is still a method that will take a decent chunk of time. And the best way is to avoid anything freezing at all, so let’s look at how we can avoid it from happening altogether.  

How to Avoid a Frozen RV Water Pump

Phew! You finally thawed your motorhome’s water pump. You’re happy to report that it’s not any worse for wear…this time. 

The more your RV’s water system undergoes heating and thawing, the higher the risk that parts can snap and crack in the brittle conditions. The following measures will help you avoid recurring instances of a frozen water pump!

Empty your Water System

This is according to me the best and most efficient way of ensuring your water system never freezes when you are not using the motorhome, RV, or caravan. If no water can freeze, you don’t have a problem!

Doing this properly every time you are not using the RV, and there might be a risk of freezing temperatures outside, has worked great for me. I never had a problem, but a lot of people are worried that there is still going to be some water left in the system that you can’t get out that will freeze.

I have seen a common way some people use to get out all the water is with an air compressor, blowing air through the whole system in an attempt to blow out the last water.

I have never done so, and I think if not done correctly and you build up to much pressure in the system, stuff can break, or a water hose might get loose, and then you will have a considerable water leak the next time you use it so be careful if you try this approach and keep that in mind.

If you have emptied your water system correctly and there is just a bit of water left in some places, the water has space in the pipes and wherever it is to expand; since water expands when it turns to ice, this can cause damage but since it is not full of water and has room to expand you will most likely be alright.

At least, this is how I do it, and it has never been a problem for me, and I think this is a more sustainable way of doing it, and it is also the easiest way that doesn’t require any extra equipment.

RV Antifreeze

Do you know how you fill your car back home with antifreeze in the winter? Well, it turns out you can do the same in your Motorhome and RV.

RV antifreeze reduces a water-based liquid’s freezing point. It comes in handy more so for pipes than it does for the water pump, but if one part of your water system isn’t freezing, then another probably won’t either.

Just remember to flush the system before using it and dump it in an appropriate disposal site.

This is a very common solution in the USA, but in Europe, and especially the Nordic countries like Sweden, where I’m from, this is pretty much unheard of. Almost no one uses antifreeze in their water system except in the grey water tank if they are winter camping with an RV that doesn’t have an insulated grey tank.

So if we in Sweden with really harsh winters manage without it, I’m sure you can too, although our RVs are in most cases built differently, and there could be a reason for this that I’m unaware of.

You can read my article on winterizing RVs without antifreeze and how I do it here or if you are sure you want to be using antifreeze in your RV while winterizing it ensure you get it the next time you go to your RV store or purchase it here via my amazon affiliate link.

RV Skirting

How does cold air get to your water pump in the first place? Well, the air currents blow under your motorhome just as they can blow around it and atop it.

With an RV skirt, cold air can no longer travel freely underneath your vehicle. You can preserve the temperature of your water pump, water pipes, and holding tanks better with an RV skirt.

This hangs down from the side of your RV to the ground. As explained previously, you could use any insulation material or whatever you have on hand, maybe some plywood sheets or what you can find, and if you combine it with a space heater underneath, you will get heated floors!

Heating Blanket

That’s right, heating blankets again! These blankets do more than thaw frozen tanks or pumps but can also prevent freezing.

The higher the voltage of your heating blanket, the better. Just lay the blanket down over your pump or the part of your water system that freezes easiest on a freezing night, and leave it there overnight. 

Some blankets are battery-powered, so you don’t have to worry about plugging them in and unplugging them. 

Insulated RV Cover 

If you do decide to winterize your caravan, you could invest in an insulated cover.

The insulating qualities will keep your RV warmer, so it’s less susceptible to the effects of the freezing chill. This would be more efficient in climates where temperatures go below freezing only at night or by just a few degrees.

If you are in the north of Sweden, it doesn’t matter how much you insulate your RV. The inside temperature will go below freezing anyway!

The cover should be waterproof too. If it isn’t, water can easily seep through the cover when it snows or rains. And the insulated cover will create a dank, dark, wet environment that mold and mildew adore. You’ll return to your motorhome in a few months to find it covered in mold! 

Heating Tape or Cable 

The last option to consider to prevent your RV water pump from freezing is to use heating tape or a heating cable. 

The heating tape features a polyblend or silicone construction. It comes in long rows and includes a power cord attached to one side. 

You wrap the tape around a surface such as your water pump, adhere it in place, and plug it in. The heat can provide about six watts to prevent the pump from freezing. Admittedly, a good set of heating tape is costly, as it’s priced at about $100, and it’s not like you can keep using and reusing it forever.

That’s why I’d suggest you look into heating cables as well. At first glance, a heating cable looks no different than your average extension cord cable. Ah, but it is!

The cable has a rounded shape so it can wrap around components of your RV, such as the pump or the blackwater and greywater holding tanks. A common thing is people put it into the discharge valve of the grey tank if that’s uninsulated to keep that from freezing while winter camping too. 

You will need an outlet, typically a three-pronged type, for plugging in a heating cable. 

The cable doesn’t stick as well as heating tape since it has no adhesive element. You’ll have to use zip ties or cords to keep the cable in place. At least it’s as reusable as your heart desires! 

Final Thoughts 

When the temperatures are frigid enough, your RV water pump and the rest of your water system can freeze. 

Prevention is truly your best means of combatting a frozen water pump, but you have plenty of options, from propane heaters to heated blankets, for thawing it if need be!