How to Correctly Find the Spot of a Leak in a Waterbed Bladder Mattress

This is the second part of our 3 part blog series:
#1: When is it OK to repair my waterbed bladder with a patch kit?
#3: Please save my carpeting! How to fix and properly repair a waterbed bladder leak
(part 3 will be linked after publication next week)

Unfortunately leaks happen and when they do and it is repairable do not put the job off.

The hole in a leaking mattress must be found:

First locate the leak in your waterbed mattress. Below are a couple methods to finding the frustrating hole in your mattress, but first be safe, you will need to unplug the waterbed heater immediately.

How to locate a hole in a water leaky waterbed mattress

Photo by: mikedefiant

You must make sure you dry up every drop of water you can get to. If you do not you will get a false positive result. This means you think you found the leak, when in reality you have only located remaining water residue from the leak you are looking for.

Ways to find the hole in the mattress

Some people recommend filling the mattress with air. Once you have inflated the mattress apply soapy water by rubbing it onto the mattress surface or applying the sudsy water with a spray bottle and wait for it to bubble up. This can be an affective method to find a waterbed mattress hole, but is often messy and could cause fiber baffle shifting if not properly handled.

The preferred method is to leave the partially filled water mattress in the wooden frame. Be sure to dry it off with an absorbent towel making sure to dry up any water remaining on the mattress. Next place your hands in a position where your index fingers and thumbs are touching as if you were going to give CPR chest compressions. This is another affective way to find a leak. Start by pressing down on corners until your hands bottom out on the floor of the bed. Next do the same with seams then all remaining untested areas. When a leak appears it will generally be a little bead or welt of water. Not a gaping gushing whole.

Once you have located the hole be sure to mark the mattress. You can do this by circling the area with a permanent black magic marker. Many people find the holes only to lose them when they walk away from the bed.

Whichever method you choose to find the leak is up to you. Eventually you will need the water mattress to be completely drained before reinstalling. This will allow you to dry the underside of the mattress. Be sure to dry up any remaining moisture within the safety liner as well.


Doug Belleville and his father Dave own and run STLBeds - a specialty sleep store located in Arnold, MO. The staff at STLBeds is highly educated about sleep, comfort and their special sleep products. STLBeds only carries high quality mattresses and bed-related products. You won't find the brand names here - just call and ask us why!

6 Comments Leave your comment »

WHat if the hole is on the underside of the matress? The top is dry, but under the bladder is wet.

Comment by Janet — December 8, 2012 @ 6:11 pm

Janet, A very good question and it is one we frequently are asked. I went ahead and wrote an article answering this question in detail. Finding leak Underneath A Water Bed Mattress The short answer is that simply because there is water under the mattress and the top side is dry it doesn’t mean your leak is not on the sides or top of the mattress because water will seek out the lowest point which happens to be under the mattress.

Comment by Douglas Belleville — December 11, 2012 @ 7:58 am

I have a leak in my 28-yr-old waterbed. First leak we’ve ever had! I bought a vinyl patch kit and we plan on giving it a try tomorrow, as our carpet is SOAKED in the corner that it’s leaking from! It’s managed to catch socks and other laundry we had near it as well as sneakers that were around the edge of the bed. Are we wasting our time patching a bed so old? Sincerely, Waterlogged Whitney

Comment by Whitney — November 9, 2014 @ 8:40 pm

Dear WW ;-) If the water mattress is 28 years old then yes you are indeed taking a huge risk. The risk is again having to clean up a big mess. Not only that but it sounds like you have a bad safety liner that needs to be replaced as well. The average life of wavier water mattresses is up to 8 years. More controlled mattresses with little to no movement should not be kept longer than 10-12 years. All of these mattresses are cheap in comparison to regular coil spring mattresses. NOTE: Be sure that EVERYTHING has been thoroughly dried out before reinstalling or mold, mildew and smell may become the new issue. Doug

Comment by Douglas Belleville — November 14, 2014 @ 8:50 am

We recently purchased a new waterbed bladder and it seems to have a pinhole. We can’t find it, have tried like crazy, and the only way we know it’s there is the underside of the blanket we use instead of a sheet to sleep on is wet in the morning. So, we know the general area of the leak, just can’t find the actual leak. Someone told us about the possibility of using a rubberized spray to fix it, like Flex Seal or some such. I worry because the product does not specifically mention waterbeds, and I don’t want to take the chance on it having something in it that will damage the bladder.

Would a spray like that be OK to use, and would it even work at all?

Comment by Susan Bell — January 8, 2015 @ 4:11 pm

Hi Susan,
I am concerned because you said this was a “new waterbed bladder”. If this is the case you should be contacting the seller to help you solve your issue. I will assume what you mean by new is “new to you”. In this case you first have to locate the leak before determining how or if it can even be repaired. Only use waterbed repair kits. You only get one shot at this.
Here is some helpful information How to Correctly Find the Spot of a Leak in a Waterbed Bladder Mattress There are also links there that can help you determine if it can be repaired and how to actually repair it. Hope this gets you going. Doug

Comment by Douglas Belleville — January 15, 2015 @ 4:47 pm

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