Exploding water filter

The Check valves in an RV are not for the same purpose as a RP Backflow preventer. Yes, I was certified to test them.

The check valves in a RV system are usually installed to isolate the outside potable water from the RV potable water tank. If you didn't have them, when you hooked up to "city" water you would fill the potable water tank. You would also charge the city water side of the RV system when you ran your RV water pump. Both sides of the RV potable water systems are supposed to be clean and potable, therefore a RP isn't required.

Gdetrailer wrote:

nomad297 wrote:
No comment, Gdetrailer?

Bruce

B.S.

You clearly do not know what you are talking about and really not worth the effort to type answer if you must know.

If check valves are unreliable as you say then why are they in nearly every device known to man?

Check valves are used in water wells (I have TWO on my water well, one at the pump 220ft below the surface and one at my pressure tank). Even vehicles have check valves (ever heard of a PVC valve?), your vehicles transmission uses BUNCHES of check valves..

Check valves are commonly used in industry and anywhere it is desired to allow flow in ONE DIRECTION only...

A check valve in the water heater cold inlet stops the water from circulating (which tends to lead to having hot water come out your cold water spigot) along with stopping any over pressure from heating the water from adding to the pressure in the cold water line.

Do check valves wear out?

Sure do.

Do they work as intended?

Sure do, until they wear out, but depending on the quality and design a check valve can last your lifetime.. If they didn't work then there would be no reason to install one..

Hard to believe but there most likely is one installed in your water heater cold inlet, it is HIDDEN and will look like an simple plastic pipe..

BOTH TTs I have owned over the years HAVE HAD a factory installed check valve. These were two completely different trailer manufacturers and different years.

Heck even with home water heaters it is a very good idea to install a check valve on the cold inlet, as I mentioned the benefit is not having hot water show up on the cold water line which can happen under certain circumstances. Plus the check valve CAN protect your cold water line from excessive pressure caused by a malfunction of the water heater T-Stat..

I STILL say that the filter that the OP was using is GARBAGE, it is a one time use and is not designed to last long... There is no comparison to the plastic wall thickness of the whole house filter I posted... The wall thickness of my home filter is nearly 1/4", the thickness of that throw away will be less than 1/16"..

I don't know who or what you think you are, but I do know you are out of your league when it comes to arguing plumbing with me.

First, yes, I have heard of a PVC valve, and there are many different types, but what they all have in common is they are all made with poly vinyl chloride. Now, I also know a thing or two about PCV valves, and I can tell you they are more of a restrictor than a check valve. Let's not get off topic, though.

Please tell me of the "certain circumstances" that will cause the hot water to flow from the cold side of a water heater and while you're at it, tell me why it is a good idea to have a check valve installed on the cold side of a residential water heater. I'm really very interested.

You see, all of this new information you provide will help me in my job. I have been plumbing for over thirty years, been a Master Plumber and Gasfitter for twenty-two of them and a certified backflow and cross-connection inspector and technician for twenty of them. I own a plumbing company and still work in the field every day. I can use all the help I can get from somebody like you who knows more about plumbing than I do. I am always eager to learn.

Bruce

Gdetrailer wrote:

nomad297 wrote:
Whether you have a pressure regulator, or not, your RV plumbing supply is a closed system -- there is a check valve preventing back flow to the city connection. When your water heater heats, the pressure in your system increases and it will only relieve at 150 psi when the water heater T&P valve opens up. So....no matter what you do, your pressure will increase above your regulated pressure if you are using a water heater.

Bruce

Sorry, not fully true.

MOST (if not all) water heaters actually have a CHECK VALVE installed on the COLD WATER side of the heater.

Many people do not realize this since the check valve is actually HIDDEN and looks like a simple plastic male to male pipe fitting sticking out the back of the tank.

Looks like THIS

and now days you may find a newer version which looks like THIS

You can verify if your system has a check valve on the cold water inlet by pressuring the system (city water port)with water.

Then turn off the water source on the inlet (inlet also has a check valve which WILL hold the water pressure from leaving via the city water port).

Open the COLD water and let the pressure bleed down then close the COLD water.

Now open the HOT water side and if you still have pressure then you HAVE an inline check valve in the cold water side of the water heater..

No pressure on the hot side then there is no check valve..

I am aware of the check valve since mine had a spring loaded one which would tend to "sing" extremely loud when any hot water was being drawn.. I replaced mine with a brass swing check valve and no more "singing".

There SHOULD be a check valve since it is a part of the safety of your water heater system. Without the check valve the T&P (Temp and Pressure relief) valve would never ever trip creating a dangerous situation to say the least..

Actually IF there are any check valves at water heater they can be on cold inlet, hot outlet or both........hot outlet is very common.

And if you have 3 valve system....no check valves.
Check valves are installed as a means of isolating water heater without installing another shutoff valve as part of bypass system.

So no.........not all RV WH's have check valves and they are not really part of any safety feature.
The PRV T&P is a Temperature/pressure Relief Valve. Opens if water temp exceeds 210*F or if pressure goes above 150 psi......it IS part of the safety features on WH's (RV, Residential/Commercial)

And 'Air pocket' (part of tank design) is what allows the expansion of water as it is heated to control pressure increases. Air can be compressed-----water can't.

nomad297 wrote:
No comment, Gdetrailer?

Bruce

B.S.

You clearly do not know what you are talking about and really not worth the effort to type answer if you must know.

If check valves are unreliable as you say then why are they in nearly every device known to man?

Check valves are used in water wells (I have TWO on my water well, one at the pump 220ft below the surface and one at my pressure tank). Even vehicles have check valves (ever heard of a PVC valve?), your vehicles transmission uses BUNCHES of check valves..

Check valves are commonly used in industry and anywhere it is desired to allow flow in ONE DIRECTION only...

A check valve in the water heater cold inlet stops the water from circulating (which tends to lead to having hot water come out your cold water spigot) along with stopping any over pressure from heating the water from adding to the pressure in the cold water line.

Do check valves wear out?

Sure do.

Do they work as intended?

Sure do, until they wear out, but depending on the quality and design a check valve can last your lifetime.. If they didn't work then there would be no reason to install one..

Hard to believe but there most likely is one installed in your water heater cold inlet, it is HIDDEN and will look like an simple plastic pipe..

BOTH TTs I have owned over the years HAVE HAD a factory installed check valve. These were two completely different trailer manufacturers and different years.

Heck even with home water heaters it is a very good idea to install a check valve on the cold inlet, as I mentioned the benefit is not having hot water show up on the cold water line which can happen under certain circumstances. Plus the check valve CAN protect your cold water line from excessive pressure caused by a malfunction of the water heater T-Stat..

I STILL say that the filter that the OP was using is GARBAGE, it is a one time use and is not designed to last long... There is no comparison to the plastic wall thickness of the whole house filter I posted... The wall thickness of my home filter is nearly 1/4", the thickness of that throw away will be less than 1/16"..

No comment, Gdetrailer?

Bruce

Gdetrailer wrote:
Sorry, not fully true.

MOST (if not all) water heaters actually have a CHECK VALVE installed on the COLD WATER side of the heater.

There SHOULD be a check valve since it is a part of the safety of your water heater system. Without the check valve the T&P (Temp and Pressure relief) valve would never ever trip creating a dangerous situation to say the least..

Sort of, but not entirely.

The problem with check valves is they are not 100% reliable -- especially those which do not comply with one of the many ASSE standards, such as those you linked to. Check valves fail quite often which is why they, in most commercial and some residential applications, must be tested and certified on an annual basis. There are companies that do nothing but backflow testing and certification because of this requirement. Almost all backflow devices eventually fail and need to be repaired or replaced at some point. Many cheap check valves don't work as you would expect them to from the start.

A check valve on a water heater has nothing to do with safety. On a small system, such as an RV, it is there to keep the hot water from migrating to the cold side, but without one, you probably wouldn't get this mixing anyway. What I'm saying is, it doesn't hurt to have one, but it probably isn't necessary. When was the last time you saw a check valve on the cold side of your residential water heater? Some, but not most water heaters have what is called a heat trap either on the top of the dip tube or within a nipple on the cold side. The heat trap is a very weak type of check valve (doesn't completely stop backflow) that is supposed to help keep the hot water from moving from the tank and into the cold water. When these fail, they cause flow problems. They are not repaired or replaced -- simply removed.

As far as the T&P not working if you don't have a check valve goes, why do you think it would never trip? When the pressure reaches 150 psi, it will open to relieve the excess pressure. It will also open if the temperature exceeds it's set temperature (usually 210 degrees) limit. A check valve has nothing to do with this.

I believe the OP has installed a filter that cannot withstand the 150 psi that is bleeding past the check valve (if there is one) when the water heater heats and increases his system's pressure.

Bruce

Wow! Lots of good input from you folks. I have been using the filter shown in Gdetrailer's photo. I used this cheap filter from Walmart for years with no problem, but them I always had it installed outside. I didn't think of the water heater pressure. Sounds like my filter became the weak link. I originally tried a hookup that looks like the the one in JFrampey's photo. I bought the Hydro Life Model HL200 from Camping World. I liked the filter specs, but the garden hose fittings always leaked after installing it inside, under the sink. I think I know why now--too much pressure. Now that spring is here I will be installing it outside where it belongs. Hey. I learned something. Thanks again for all the ideas.

nomad297 wrote:
Whether you have a pressure regulator, or not, your RV plumbing supply is a closed system -- there is a check valve preventing back flow to the city connection. When your water heater heats, the pressure in your system increases and it will only relieve at 150 psi when the water heater T&P valve opens up. So....no matter what you do, your pressure will increase above your regulated pressure if you are using a water heater.

Bruce

Sorry, not fully true.

MOST (if not all) water heaters actually have a CHECK VALVE installed on the COLD WATER side of the heater.

Many people do not realize this since the check valve is actually HIDDEN and looks like a simple plastic male to male pipe fitting sticking out the back of the tank.

Looks like THIS

and now days you may find a newer version which looks like THIS

You can verify if your system has a check valve on the cold water inlet by pressuring the system (city water port)with water.

Then turn off the water source on the inlet (inlet also has a check valve which WILL hold the water pressure from leaving via the city water port).

Open the COLD water and let the pressure bleed down then close the COLD water.

Now open the HOT water side and if you still have pressure then you HAVE an inline check valve in the cold water side of the water heater..

No pressure on the hot side then there is no check valve..

I am aware of the check valve since mine had a spring loaded one which would tend to "sing" extremely loud when any hot water was being drawn.. I replaced mine with a brass swing check valve and no more "singing".

There SHOULD be a check valve since it is a part of the safety of your water heater system. Without the check valve the T&P (Temp and Pressure relief) valve would never ever trip creating a dangerous situation to say the least..

Gdetrailer wrote:

Snohotom wrote:
Thanks for the feedback folks. To clarify, I have always used a pressure regulator between the outside faucet and the incoming hose. My pressure measures 45 PSI before the regulator. The old regulator was rated 40-45 PSI. I can't see how one of these could go bad. There are no moving parts. I changed out to a new one just to be safe. They are pretty cheap. I suspect a possible line surge may have overwhelmed the regulator. I do have a quality filter that I used in the summer, but it will not fit under the sink.

You didn't give a model number but I am betting the one that is blowing up looks like

THIS ONE

Which is a cheaply made one time use filter for $16, you HAVE to replace the entire filter every 90 days and if you are not using it it is impossible to really safely "store" it (IE you can not dry it out to store which can allow unwanted bacteria/mold to grow inside the filter)...

I am thinking that with a little creativity on your part you WOULD be able to "find" a place under your sink or even nearby to install a filter like I linked in my previous post...

Right now, you ARE buying a cheapo ONE TIME USE filter, it is not designed nor intended to be permanently installed and left there forever.. The results of such a cheap filter IS the possibility of breakage..

The one that I had looked exactly like this one:

WaterPur Filter

Commonly installed in many RV's. I replaced it with one very similar to what Jframpy posted.

Here's my water filter install...



Picked up the filter body at homedepot... Whole house filter < $30. I can use standard sediment filters or charcoal if needed. After ea trip and when winterizing I remove the filter and let it dry out. I need to rig a "bypass" for winterizing... The filter housing fills up with antifreeze!