Latest Discussions : Bathroom

BV005838

03:28PM | 09/28/14
I live in a 15 yr old home about 1500sq ft, 3 br, 2bt. The gas water heater is the original. Do you think I should get a tankless gas water instead of a gas tank water heater?

BV000193

03:37PM | 09/28/14
Hell No.

BV005838

03:50PM | 09/28/14
Then I should stick to a gas tank water heater?

BV000193

06:18AM | 09/29/14
Right.

BV000193

06:35PM | 09/30/14
These are the words of a Licensed Master Plumber who shall remain anonymous.Ok I have been servicing tankless heaters for a little over 10 years now. Here are the issues I have ran into.

Longevity is over rated. Most manufactures lowered their warranty period accordingly. I had dozens of various brands have part failures within 5 years of operation.
Parts can take a few days to a few weeks to get. No local supplier carries any of the parts. If the manufacture distribution warehouse in the states has the parts you get them in days. Otherwise the parts come from the country of origin and can take weeks. I had one part take 2 months to get.
When one of the many water connections inside get a pinhole leak (Supply pipe, heat exchanger, outlet pipe, bypass pipe) they tend to leak on the electronics. I have had two units that the electrical companies literally burn up, what kept the unit from starting a fire was the leak itself and the breaker eventually popping.
In the above situation it was a commercial job with multiple tankless heaters installed. The burned up unit needed to be replaced, the issue is with a system controller it must be the same model as the other. In both cases the model is no longer available. It was not just a model number name change (Noritz did this once so the newer model number names are the same as the older models) It was a flat out discontinuation of the model. So in other words if the owners wanted to get back to full capacity they would need to replace all the heaters, in these cases that would be six heaters.

There is more but these are the major issues I do not recommend installing these for a residential application. If I have a customer that wants a tankless system installed in their home, first thing I do is explain to them its in their best interest to install (2) two units, this way if one needs parts they will still have hot water while waiting on the parts, even though limited in capacity. I also explain to them they must, let me repeat that they MUST ensure the gas supply is properly sized to handle the increased BTU demand. The so called claims that the heater will "suck" the needed gas through a 1/2" line is total BS.

This last winter I had so many people call me due to no hot water calls.. Some issues were the gas meter was not rated for the total demand of the furnace running and the tankless at the same time. Another issue is undersized gas lines, many installers fell hook, line and sinker for the BS that some manufactures put out there saying their units work fine with a 1/2" supply. When the heater needed to run at full capacity (lots of people don't realize the heaters modulate for demand) it is no longer getting the needed supply of gas to run at the 199K+ BTU's especially in most cases the 1/2" line is tapped right off the 3/4" supply pipe that also supplies the dryer, and furnace. A couple other issues had to do with venting.

I remember when they first started marketing tankless water heaters, they used to always state how they used them for 50+ years overseas. What they failed to tell you is they rarely if ever used a single unit for the whole house. They installed multiple units at the point of use. In such an install, the heaters can be sized for the demand of water at the point of use, and only run part time so yes they will have a longer life.

BV005945

12:50PM | 10/07/14
Thank-you for your input.


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