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fug

Jan 21, 2012, 12:43 PM

Post #1 of 25 (10746 views)

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Tankless water system

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Also known as an on demand system. Installed one in August to the tune of 5000 plus installation. It is electronic ignition and stopped lighting after two weeks. Called the company as it is under a five year warranty. First company rep said not enough water pressure to cause ignition. Told us to remove all filters, single handle faucets, replace kitchen faucet, replace showerhead to increase water pressure. We did. Same problem. Called company again. Second guy said unit was faulty and replaced it. Two weeks later, same problem. Called company 7 times over a three week period they finally sent someone out today. He said the water pressure was too high. Yup, the exact opposite of what the first guy said. He also said that a part needed to be replaced to the tune of 700 pesos, which was damaged by the high water pressure. Made zero sense, but I want hot water after five months of going through this. I gave him 700 pesos and it worked fine when he left. Two hours later, no hot water. I am beside myself and do not know what to do. What I think I am asking for is the most qualified person that you know that has the most technical knowledge of on demand systems, not just a great plumber. I have one and he is beside himself as to what to do also and this is a guy who has done whole house plumbing and electrical with no problems. Yes, I am on a rant. Thanks for noticing. All I want is consistent hot water after five months. My neighbors are getting tied of me showering in their homes and so am I. fug

(This post was edited by fug on Jan 21, 2012, 1:25 PM)

Chapala Payaso

Jan 21, 2012, 6:50 PM

Post #2 of 25 (10699 views)

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Re: [fug] Tankless water system

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I had similar probles with inadequate hot water with my tankless water heater. Looking back on the issue, I believe that the flow rate was inadequate to keep it lit and so I was always on a hot and cold situation. I replaced it with a continuous flow heater that has a 9 liter tank. So if you turn the unit on to wash out a glass or such, hot water is available. In the coldest months, I turned thermostat up since it was taking too long to heat the water in the pipes. That solved that problem. The continuous flow heaters seem to me to work the best.

sfmacaws

Jan 21, 2012, 8:59 PM

Post #3 of 25 (10687 views)

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Re: [Chapala Payaso] Tankless water system

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We originally had one of those Bosch on demand water heaters, what a PITA. It was instant hot AND instant cold usually just as you got the shampoo in your hair. The only way to keep the hot water on was to run the hot faucet in the sink during your shower. It made me nuts and I had them take it away after 3 Bosch technicians came out and tried to fix it.

My guess on the problem is that we have a pressure system, the pressure pump goes on and builds the pressure up in the tank to a set level and turns off. When the pressure drops below another set number the pump goes back on. I think the on demand heater read the difference when the pump turned on and off as demand stopping and shut off the heat.

Whatever, I am much happier with my normal tank water heater. I usually turn it off in the summer anyway so I'm only using it during the winter. Mainly, it just works. I have all the hot water I want and it doesn't turn cold in mid shower.

Jonna - Mérida, Yucatán

morgaine7

Jan 21, 2012, 10:11 PM

Post #4 of 25 (10680 views)

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Re: [fug] Tankless water system

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I had OD water heaters (in another country) … never again. In the first apartment, there was rarely enough pressure to light it, and installing a pump would have affected other people's pressure in the building. I had to move. The OD heater in my next place worked better, except when it didn't work at all. I finally had it replaced with a tank heater. I shudder when I think of all those cold showers, aarrgh!!

OD heaters are no doubt designed for consistent, reasonably strong pressure, not for gravity systems or pressure tanks or shared pumps or any of the other setups that are common here in Mexico. Maybe they'd work if you also had an on-demand pressure system, I don't know. My contractors installed a large (70-some liter) Cal-O-Rex tank heater that is way more than I need. It cost about 2,300 pesos plus installation, uses very little gas, is easy to light, heats quickly, and has given consistent hot water for almost five years. Like Jonna, I don't even need it in summer. If it blew up tomorrow, I'd go out and buy the same model again.

Kate

robt65

Jan 21, 2012, 10:57 PM

Post #5 of 25 (10675 views)

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Re: [morgaine7] Tankless water system

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Good Morning All,

Thanks to all of you for your comments for OD water Heaters. We are almost finished the remodel of the home we bought and are preparing to move in next two weeks. then we start planning the addition of the master bedroom, master bath and laundry room. I have been toying with the idea of an OD water heater, but this and other earlier posts have finally put the "kybosh" on OD Heaters for me. So if all those cold showers have any comfort at all, I guess it is for me. As you have all said, . . . . . . . it just works! That just about says it all. Even though we have a single story home, and the pressure is surly missed, we are planning on installing a 10 K liter in ground Rotoplas cistern for the showers and new laundry room. It seems to be the perfect fit with two filters and a pressure system. We are also going to be drilling a well for additional backup for water, should the need arise. Thanks for pushing me off the fence!

robt65

whynotwrite

Jan 22, 2012, 5:55 AM

Post #6 of 25 (10661 views)

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Re: [Chapala Payaso] Tankless water system

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Reading the manual to the OD heater is very important. It does explain the fact there is a flow sensor that must "see" water flowing before the gas is opened. No water flow, no gas, no hot water. In Mexico the problem is low pressure in almost all cases.
This turns out to be a do it yourself project since finding someone who will read the instruction manual and install the OD water heater per specs is not easy. Plus the fact the install is going to cost you more due to the water pressure problem. Rotoplas sells a booster pump, a neat little designed pump, that is made to correct the problem of low water pressure and will be part of the install cost in most cases.
On Demand water heaters use a fraction of the gas of tank type water heaters. Installation per the manual´s specs is more costly than you might wish but you will likely see the gas savings in less than 2 years. Getting someone to install it per spec. it seems is the hardest part of the project.

johanson

Jan 22, 2012, 6:09 AM

Post #7 of 25 (10660 views)

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Re: [whynotwrite] Tankless water system

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Just a thought. When I remodeled I put in both an instant on hot wate system and a solar panel in, 3 years ago. I've never had a problem with my instant on system, because I have never had it on. I just use the hot water from my solar panel. yes sometimes in the morning following a cloudy day, the hot water isn't ideal, but it has never been that bad.

Try solar, just make sure it's properly sized and when putting in the hot water pipes, why not insulate them. It's all worked for me

robt65

Jan 22, 2012, 6:41 AM

Post #8 of 25 (10657 views)

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Re: [johanson] Tankless water system

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Good Morning Pete,

My neighbor just installed the same setup. He is also using the OD and Solar combination, but it is not only those "day after the cloudy days" that is a physical affront to this old body (the body retaliates) and certain appendages seem to almost disappear! (smiling) I am one of those guys that has to have steam vapor rising from the shower before I will step in! The one thing at my ripe old age refuses to give up SOB is a strong and consistently hot shower!

I also think that since this in ground Rotoplas system comes with a double filter as well as a water pressure pump, it is just more cost effective for me all around. No more water "slowdowns" from the local govt., and this in turn also helps my washing machines as they do operate better on a consistant NOB pressure system as well as getting hot water constantly and worry free. This is much easier on the machines for sure.

robt65

(This post was edited by robt65 on Jan 22, 2012, 6:44 AM)

sfmacaws

Jan 22, 2012, 10:08 AM

Post #9 of 25 (10629 views)

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Re: [whynotwrite] Tankless water system

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My OD heater was properly installed by Bosch technicians, it's kind of snide to imply that no one read the manual. I read it, the plumbers read it, the architect read it, and the Bosch guys seemed to know it by heart. Also, we did have a separate pressure system that is still working great. There is more to it than your facile assessment. It not only needs to 'see' water pressure, it needs to see a change in water pressure. That is the problem unless you keep the pressure pump running for as long as you want hot water, which is why turning on a hot faucet elsewhere worked. It's an enormous waste of water to save a very few pesos in gas.

I agree about the solar heaters, they work very well for friends that have them. If I were doing it all over I'd probably go that route with perhaps a small tank backup. My preference is to shower at night and I too want almost endless hot water in the winter, in the summer the water from the tinaco is a perfect temp so we turn off the heater. In fact, in the summer if I want cooler water for a shower in the daytime, I use the hot faucet because the water in the turned off water heater is generally cooler than the water from the beige and insulated tinaco on the roof.

Jonna - Mérida, Yucatán

whynotwrite

Jan 22, 2012, 11:34 AM

Post #10 of 25 (10618 views)

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Re: [sfmacaws] Tankless water system

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Take a minute to read your post. The sensor needs to see XXX psi and if your not supplying the required psi it will not open the gas valve. Too simple for words, you answered the question yourself. . In Mexico the electrictians hate using a meter and plumbers dont use gauges to check pressure.

Chapala Payaso

Jan 22, 2012, 12:02 PM

Post #11 of 25 (10616 views)

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Re: [whynotwrite] Tankless water system

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When using the tankless system, I had a pressure pump that comes on when a spigot opens dropping the pressure. I had pressurized hot - cold-hot continuously causing me to jump one way and the next. With my present system, I have a 9 liter tank continuous flow heater. Once the thermostat was adjusted correctly I now have hot water which never quits. It is the best of two worlds. The amount of gas necessary to maintain the 9 liters is very small and when it fires up with the pressure change, it remains hot. One thing I may do next cold season is to insulate the pipes on the roof from the heater to where they plunge into the house. I too like endless showers in the morning and for me this is the best system. However, I have never had solar.

sfmacaws

Jan 22, 2012, 12:55 PM

Post #12 of 25 (10604 views)

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Re: [whynotwrite] Tankless water system

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I'd love to have an electronic ignition on my regular heater. Living alone I rarely use hot water but the good old pilot light is out there burning day night and weekend.
http://www.chapalaweather.net

YucaLandia

Jan 23, 2012, 10:12 AM

Post #23 of 25 (10498 views)

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Re: [whynotwrite] Tankless water system

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In Reply To

What specific OD water heater models and brands have you found work well and reliably?

sfmacaws experience is similar to the one we installed for a friend. His hydropneumatico is a large capacity, reliable system set to 25 - 30 psi of working pressure. The Bosch OD units sold in Mexico simply do not work as advertised, even when installed by a professional, precisely following the manufacturer's instructions.

As sfmacaws described, even when the official Bosch technicians come out and inspect and try to adjust - even with pressure systems - these systems simply do not work as expected. Do we imagine that 4 different official Bosch technicians do not know how to install or maintain their own hardware?

Continuing with other brands:
I've installed and worked on "Cinsa de Paso" and "Cal-O-Rex" units - where the manufacturer uses a high capacity burner and a cylindrical tank with special baffles for transferring heat - no flow sensors and no pressure sensors - and these work for about 6 months to a year - then they fill up on the bottom with solid sarro - scale - filling as much as 1/3 of the tank with a big block of near solid white crystalline CaCO3 that reduces capacity and causes the heater to shut off prematurely. Rinsing does not help. Adding a liter of muriatic acid helps a little - but may be hard on the copper tank. The best solution we've found is to remove the Zn rod, and ram a piece of 3/4 in PVC down the hole - over and over - to break up the block of crystallized scale - and also remove the drain valve to offer a drain hole big enough for chunks to come out, and then use a hooked wire to fish out the chunks through the drain cock hole, while flushing with water and chopping/poking with the PVC... The last one took 45 minutes of chipping and flushing to remove a substantial pile of sarro chunks.

Is this really a big savings, when it takes disassembly and 30-45 minutes of vigorous messy effort to keep an OD heater running and not shutting down prematurely?

Indugas's Splendid OD units have been the most reliable OD heaters we've found here - not finicky with low pressure - but their capacity is quite small.

Really, unless you know the specific brand of heater, how sensitive it is to flow or pressure, and how quickly they plug up (even the Bosch units plug up rapidly when they do work), then the advice of people who have not installed and maintained your specific unit for more than a year, probably does not fit the quirks of your specific OD heater.

I've only worked on about 9 OD units here in Mexico, and only one has worked as hoped for.
steve
-
Read-on MacDuff
E-visit at http://yucalandia.com

whynotwrite

Jan 24, 2012, 8:28 AM

Post #24 of 25 (10441 views)

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Re: [YucaLandia] Tankless water system

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Steve, You are quite the wordsmith. Talking the talk and walking the walk is two different things. I am not a wordsmith, will never be a wordsmith and have never desired to be a wordsmith.
On demand water heaters are used all over the world, besides here in mexico. Thinking there is problem in Mexico that prevents them from working correctly is talking the talk.
Referring to “official Bosch technicians” means little or nothing. I worked as a factory service tech and not knowing the problem and being able to solve the problem is not an option. They did not solve or even (it seems) know what the problem is that prevents the OD heater from working.
Go back and do another google search and write me with another 12 inches of print.

Maesonna

Jan 24, 2012, 8:58 AM

Post #25 of 25 (10437 views)

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Re: [fug] Tankless water system

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We have a tankless Delta which has been working well for 10 years except that one of the pilots tends to go out and you have to relight it from time to time. It started leaking just a few weeks ago, and I was thinking of replacing it with an electronic ignition one, but after reading about the problems several of you have had, I think we are better off with a pilot model again, because unlike the electronic ignition kind, they are not fussy about water pressure and distance from the service point (bathroom).