Full Article at: ” Considering Adding a Pressure Pump (Hidroneumatico) to Your Gravity Feed System? “ About every 6 months, someone new pops onto Mexican expat construction and home repair forums and asks about the in’s-and-out’s of improving their household water pressure by adding a hidropneumatico (pressure-pump) that includes a bladder & tank system.
There are a number of issues and alternate problems that need to be considered first before choosing to install a pressure pump system on an existing gravity feed water system. If you rule out other likely problems, and still need/want even higher pressure, then there are also issues to consider about what type of system to buy, how to protect it from the weather and sun, and who to hire to install it.
Common misconceptions and frequent advice that is off the mark ….
* * * *
Read the Full Article at: ” Considering Adding a Pressure Pump (Hidroneumatico) to Your Gravity Feed System? “
* * * *
Feel free to copy while giving proper attribution: YucaLandia/Surviving Yucatan.
© Steven M. Fry
Read on, MacDuff.
Surviving Yucatan 
Pingback: Pump to increase water pressure in house | Living in Cancun & Riviera Maya Forum
I need some help with my hot water. I have a new 2 story house. The water pressure seemed pretty good until I set up a instant hot water gas tank. Its Cal-o-Rex brand from home depot model COXDPI-07. They make a larger model but my house is only 2 bathrooms. So I had a handy man set it up. I really dont think he understood the unit. He did not believe it needed a vent for the gases to go outside. this unit is set up in my laundry room. The guy thought it was too far away from the bathroom but the washer is withing 4 feet of the unit so at least the hot water should have come to that faucet. I realized that no water at all was running from the upper level hot water faucet of the shower. a friend suggested there might be an air lock so I ran the water for 1.5 hours and finally started getting some water. I did get the hot water tank to work but it seems that it takes 4 minutes for the water to reach my upper shower and it does not stay hot. It is on the highest setting and still goes intermittently cold. Interesting, the sink in the same bathroom gets hot much faster. My kitchen sink is about 12 feet from the heater and the cold water pressure is great but the hot water side just dribbles. I was thinking I need a water pump and wondering if you have some suggestions. Maybe I do have more air in the system but I have no idea how to get it out. Suggestions please?
Hi Donna,
When we buy an on-demand (de paso) heater, if we are running just gravity feed from a tinaco, we need to pick a model specially designed for NO pressure pump.
Cal o rex sells them – in a version that’s round & looks like their regular tank water heater … but the de paso version has a special small copper tank with a special burner. THAT model gives almost full flow, even with a gravity fed roof-top tinaco water system.
It sounds like your Home Depot guy mistakenly sold you the rectangular Cal O Rex boxy unit that hangs on the wall – a model with SUPER NARROW tubing inside.
That model requires a special small pressure pump – to force the water through its very small internal tubing.
That model also has huge problems with getting clogged with sarro (calcium scale) if your water is even slightly hard.
It can take a special pump to force strong acid – and circulate strong acid through that unit’s very small internal tubing.
*sigh*
So… you need to either buy & install a small pressure-switched pump … a pump that has its own pressure sensor that turns the pump on only when you open a hot water spigot. The cheapest versions cost about $40 USD … up to about $90 USD.
The downside of adding a pressure pump to your hot water plumbing??
Many many many many Mexican homes have weak plumbing joints inside our walls & floors … that do not leak under the low pressure of gravity fed rooftop tinacos.
… but when we add a pressure pump (even at just 20-25 psi), we can cause the often-weak Mexican home plumbing to start to leak … inside our walls & under our floors … in hidden leaks … that we only find because the pressure pump keeps turning ON when we have not run any hot water… *sigh*
The other alternative would be to take the Cal O Rex model BACK to Home Depot, and require them to give you credit to buy the correct model that works with your low pressure water…
??
steve
**I’ve done both solutions (take it back or add a small pressure pump) … and I’d personally take it back and get the correct model … because the model you have generally requires a lot more maintainence than the de paso model with a small (7L?) tank…
Thanks for your reply. I cannot return the unit since I purchased in last March and just had it installed. I already tossed the box and packing materials. But that being said. I have to go to Chetumal tomorrow and I will stop by at home depot and consider getting the larger round model, Is this larger round model intended to be placed inside because that is my intent. I hate those ones on the outside, they rust out within 3 years. All the pipes are concealed in the walls and even though they look like the green type that required that heating up tool for connections, I dont need any leaks. I think think I may have some air in my pipes since the pressure is so different from hot and cold. any tips to get rids of potential air locks in the system?
Steve I am looking at the home depot web site. Is it possible for you to send me the link to the one you think I should get along with the tips for getting rid of the air locks in the pipes thanks
Donna you need to vent the burnt gases outside. Knock a hole in the wall or out a window, but it must be vented… as my dad used to say “you could wake up dead” 🙂
Electric heaters suck lots of power, but they don’t expel burnt gasses.
I understand I have to vent the gas outside but some of the heaters are designed to be installed outside and thus automatically are vented. Mine will be inside the laundry room and yes I can vent it but I want to understand the exact model you are suggesting because my spanish is not good. It will be difficult for me to explain I need a low pressure system and frankly, I am not sure all the home depot workers understand all this kind of stuff
Hi Donna,
I believe these models of Cal O Rex de paso heaters do not require a pressure pump:
http://www.calorex.com.mx/calentadores/calorex/de-paso/de-paso-standard/calorex-coxdp-11-gas-lp
Maybe you can explain something crude like:
” Tenemos un tinaco, sin bomba de presión, sin hydropneumatico. Entonces, necesitamos un calentadora de paso por systemas de bajo presión de agua. ”
Basically explain that they did not ask you the correct questions, and they sold you the wrong heater.
… Maybe take a friend who speaks
Spanish.
or… IF your water is reasonably soft, then add a pressure pump to the hot water side of the system.
Good Luck
Just returned from Home Depot. They had that Cal o Rex model you mentioned but the expert in the store after readying my note in spanish about my house and 2 banos, thought I would have the same problem with that model. I noticed a Bosch that claims to be good for 2 showers at once. http://www.homedepot.com.mx/comprar/es/coapa-del-hueso/calentador-agua-instantan-silver-13l-lp I purchassed this one. I am hoping you will read the specs and tell me I made a good choice before installing it. thanks for all your advice.
Hi,
I wish I had better news.
That rating for 2 showers says it will make enough HEAT for 2 showers … but ONLY when driven by a pressure pump.
I’ve only installed 5 different Bosch heaters of this type … and all 5 required pressure pumps …. and NONE of the 5 worked for more than 18 months. … All 5 ultimately failed for various reasons … 2 died of poor circuit boards … 2 got fatally plugged with sarro-hard-water-scale … and the last one cycled ON so much, the owner put in the recycling bin out of frustration…
I still think all the ‘Instantaneo‘ units need a pressure pumps, while the ‘De paso‘ units can work on roof-tinaco gravity pressure.
After having to deal with 2 hrs to 5 hrs on the phone with Bosch Tech Center in Mex. City on each of the Bosch heaters I’ve dealt with… I really would avoid the Bosch On-Demand models.
I so appreciate your advise. Unfortunately I jumped the gun and already installed it. It seemed to turn on but then not. I guess I did not understand the difference between El Paso and instantaneous type. I think I will just invest in the pump at this point so the question now is should I invest in the small red pump or a hidroneumatico system. Comments?
small pump.
KEEP & SAVE all your paperwork on the Bosch heater, as I’ve had to deal with 4 different warranty problems with them.
GOOD LUCK !
steve
At this point and now being the proud owner of 2 instant hot water tanks, I am trying to find a local professional plumber. Many of the local men here in Mahahual will attempt to make anything work but really have no idea. There is a problem somewhere because I was able take a cold water shower last night and woke up this morning to no water at all. the city turns it on for certain hours during the day and so I am waiting. I have not used my entire tinaco of water. I need to figure this out, pump or not. I just want it to work when I turn the faucet on. thanks for all your tips.
Re getting air out of the system… Are you sure that the problem is an air lock? I think the problem is that your gravity feed tinaco on the roof system just does not make enough pressure for the small restrictive tubing in your on demand (instantaneo) heater (a rectangular box heater that hangs on a wall).
If you really are convinced you have an airlock, I’ve have good luck sucking out air bubbles in 2’nd floor plumbing using a garden hose.
Connect the garden hose to a spigot. Run the hose up to the 2’nd floor water circuit that has the air lock. Turn ON the spigot until the hose is full of water. Connect the hose to a faucet on the air-locked circuit.
Now, down at the 1’st floor spigot, kink the hose (to stop water flow) … then disconnect the hose from the spigot.
Then move the hose to a place for it to drain at ground level.
The full hose provides a powerful siphon that sucks the air out of the pipes…
Good Luck,
steve
GOOD POINT.
In the midst of addressing the other issues, I forgot that one.
Donna: “Unfortunately I jumped the gun and already installed it. It seemed to turn on but then not.” so it does not work as recommended. Return it Now.
yes, pumps are good, cheap ones may nor be near as good.
Home Depot should refund your money.
There should be a true plumbing supply or pump supplier around town. Find one and you should happy.
agreed…
*sigh*
Since I have already installed this unit. Do you think home depot would take a return. I still have the box and stryofoam.
Here in Ensenada, BC… yes Home Depot would take a return in your circumstances.
Go ask and present your complaint about bad advice/recommendation from their employee.
as far as those on demand heaters, opinions vary. we went to a common gas tank type heater several years ago. trouble free. gas consumption is about the same.
Good luck, Peter