Forums > Specific Focus > Home, Garden & Construction in Mexico

tony

Feb 18, 2008, 4:39 PM

Post #1 of 10 (4167 views)

Shortcut

Water Heater question

Can't Post | Private Reply

Hello,

We are about ready to pick out the water heaters for our house. Given the size and general
lack of water pressure, we want to install a large one for the main part of the house. We
want to install a small one for a master bedroom/bathroom. It was recommended to get
a type of "on demand" gas heater. I don't know anything about these. Someone else told
us that these tend to have problems. Anyone have experience with the smaller on demand type
heaters? Any comments appreciated.

Sincerely, Tony

"We don't see things as they are, we see things as we are."

heff

Feb 18, 2008, 6:24 PM

Post #2 of 10 (4152 views)

Shortcut

Re: [tony] Water Heater question

Can't Post | Private Reply

Tony,
We have only the "on demand" type water heater in our home and find it to work very well. We have a rather large house and occasionally have had guests in 4 bathrooms taking showers etc in the the morning without a problem. I dont have the economy info but it is claimed to be much more efficient than the conventional tank type heater. Ours is propane gas heated.
Chuck

morgaine7

Feb 18, 2008, 8:03 PM

Post #3 of 10 (4144 views)

Shortcut

Re: [tony] Water Heater question

Can't Post | Private Reply

Here's a 2007 discussion on another forum: http://forums.bajanomad.com/...thread.php?tid=22615
My personal experience with this type of heater (years ago, not in Mexico) was negative. Without consistently strong water pressure, it simply did not work much of the time. If you go this route, be very, very sure that your water pressure is adequate to operate it.

Kate

NEOhio1

Feb 19, 2008, 6:42 AM

Post #4 of 10 (4128 views)

Shortcut

Re: [morgaine7] Water Heater question

Can't Post | Private Reply

We too just went thru this decision making process. Water Pressure was the big issue. The second big issue was manufacturer, virtually no one who owned the Bosch system was happy with it. and some people were happy with the Calendor??? brand. Our home has two water heaters, one for the front of the house serving the small bath, kitchen and laundry, and another for the back of the house serving two full baths. Both of these were inadequate because they were 72 liter tanks, a bit over 20 gallons. WE hadn't noticed that they were less than half what we were used to having because they are the same height, but narrower. I hadn't been able to locate a 50 gallon hot water heater until just recently. We opted for the 50 gallon tanks instead of the on-demand heaters. Frankly we knew the 50 gallon tanks would be sufficient and weren't willing to "spend the money twice" if the ondemand system didn't perform well for the back bathrooms. The cost of gas was not a factor in our decision as its impact on our budget is negligible being under $5000 pesos per year. Of course now we will be heating twice as much water but for us the sure thing of 50 gallons versus a maybe okay system of ondemand was a better deal.

Ed and Fran

Feb 19, 2008, 7:51 AM

Post #5 of 10 (4119 views)

Shortcut

Re: [NEOhio1] Water Heater question

Can't Post | Private Reply

We recently (2 months ago) installed a Bosch instantaneous water heater for our bathroom. So far we have been very pleased with it. Who knows what will happen in the long term, but it's just what we wanted.

For us, gas usage wasn't the issue. Space was. The heater needed to mount on the wall just outside the bathroom and not overly restrict access through that walkway. The Bosch unit is only about 6" think, so you barely notice it on the wall.

We were concerned about whether our water pressure would be adequate for the heater to operate properly. So on the dealer's recommendation we installed a small in-line pressurizing pump in the water supply line just before the heater. This pump has it's own flow sensor. On detecting flow of water in the line the pump starts and boosts the pressure in the line downstream of the pump (as opposed to a hydropneumatic system that would pressurize the entire house plumbing system) sufficiently for the heater to operate.

So far it has operated extremely well.

Just one more data point.

Regards

Ed & Fran

robrt8

Feb 19, 2008, 10:26 AM

Post #6 of 10 (4110 views)

Shortcut

Re: [Ed and Fran] Water Heater question

Can't Post | Private Reply

Ed & Fran,
Where did you find this in-line pump? This sounds like what I've been looking for.

Ed and Fran

Feb 19, 2008, 11:32 AM

Post #7 of 10 (4102 views)

Shortcut

Re: [robrt8] Water Heater question

Can't Post | Private Reply

We got it in Mexico City, but I suspect you could find it in most big cities. We were buying the instantaneous water heater there, which is why we picked this up at the same time. (No, instantaneous water heaters are not available in Tuxpan. Maybe in Poza Rica, but we didn't look since we already planned to be in the D.F. for other reasons.)

It's made by Grundfos. Here's the webpage for Grundfos Mexico
http://www.grundfos.com/web/HOMEmx.NSF

I'm pretty sure this is the model. Ours is slightly different, mainly in the arrangement/mounting of the flow sensor, but this is probably the current design.
http://www.grundfos.com/...ebopslag/PMAZ-5C5U39
The body of the pump is about 4" in diameter, and it's about 6" from front to back. Mounts in the water line, water in the bottom and out the top. Our plumber fastened it to the wall with a U-bolt.

Regards

Ed

robrt8

Feb 19, 2008, 6:12 PM

Post #8 of 10 (4078 views)

Shortcut

Re: [Ed and Fran] Water Heater question

Can't Post | Private Reply

Thanks a lot. This is exactly what I've been looking for! Muchisimas Gracias Ed.

Esteban

Mar 9, 2008, 10:46 AM

Post #9 of 10 (4035 views)

Shortcut

Re: [robrt8] Water Heater question

Can't Post | Private Reply

As a side note, I have maintained these on demand heaters. One of the biggest mistakes made, which will give you fits, is that the vents have to be installed properly and with the correct size. If not, the heat exchangers will soot up and shut off.
It's a hassle to pull the heat exchanger and clean them. The vent pipe should be at least 6" in diameter and go STRAIGHT up...no elbows. Clean water, free of particulates helps, the correct pressure as noted but when all the ducks are in a row, they work fine.

Oh yea, one more: Make sure the piping is the correct size. Many plumbers tend to undersize the copper.

Hope that helps.

Ed and Fran

Mar 9, 2008, 5:02 PM

Post #10 of 10 (4012 views)

Shortcut

Re: [Esteban] Water Heater question

Can't Post | Private Reply

Oh yea, one more: Make sure the piping is the correct size. Many plumbers tend to undersize the copper.

That's the main reason we went with the pressurizing pump. We have enough vertical head, but the original plumbing was run with 1/2" copper instead of 3/4", so there's a big pressure drop by the time it gets to the heater.

Ed