Just a suggestion to talk to your gas provider re your meter. They can provide a worksheet and tell you your options for a larger meter. My local provider had an option for a larger meter (which was free) and an even larger option that did involve an up charge.
On Demand Hot Water and gas lines
- Thread starter Cheese
- Start date
My musings on this subject after reading the whole thread:
Sorry mino & Coen, this is an American site and building practices/ products that work and or are prevalent in Europe don't often work here - if they are available at all. Electric on demand water heaters are one such thing. Those that will run a typical sized American house are not practical to integrate into 99% of existing home's electrical service. And if you wanted to start from new - the economics still don't make sense because there are few (if any) places in which the cost of delivered electricity is cheaper per BTU than natural gas or Propane. And tradesmen are not as well trained and regulated as they are over there. It's quite common for regular people to have more experience and do a better job than many tradesmen that show up to out homes these days. Sad and concerning - but true.
Yardbird - strictly speaking, your meter is undersized, but......... Your Rinnai will modulate the gas usage depending on the incoming water temp and the demand called for. So in the summer if you're just running a bath faucet, it's not going to use many BTU's and you'll be more than fine. In the wintertime, well...........could be a problem. You incoming water temp. is much lower than mine in GA and will require more BTUs to heat to hot. If your temps are realllllllly cold and your furnace is running full tilt and you turn on a tub filler - your system will likely be starved and either the furncace or heater will suffer depending on the home's piping layout. Turn on a gas cooktop or oven at the same time and things get worse. Think Thanksgiving.
oberlin1 gave solid advice - call your gas provider. Their engineers will help you calculate your demand needs and will provide a new meter for you. Go bigger than you think you need because you/others may upgrade to a bigger or second unit, add a pro cooktop, a kiln, forge, patio heater, BBQ, ect.......... Better to have the capacity and not use it than to need it and not have it.
et al - For those that care, these things are not silent. There is a fan that runs during operation and while it's not what I'd call loud or noisy - it is audible. And depending on your mounting location, and hookups you may get resonance into the building structure.
There are/used to be apps from the CSST pipe co.'s that will help you size piping systems.
Rinnai now comes with a flush kit as standard. If your heater doesn't have one GET ONE. Plumbers around here will not install a unit without one, and even if they did - it's poor economy to not get one.
If building new or doing a heavy remodel, I recommend locating the water heater in the center of the home and using a manifold to home run all the service lines back to. This cuts down on wasted water while waiting for hot water to arrive and makes it easier to service & remodel during the home's lifespan. Low demand fixtures can be plumbed with 3/8" PEX for even quicker delivery. Though that creates material supply headaches.
Sorry mino & Coen, this is an American site and building practices/ products that work and or are prevalent in Europe don't often work here - if they are available at all. Electric on demand water heaters are one such thing. Those that will run a typical sized American house are not practical to integrate into 99% of existing home's electrical service. And if you wanted to start from new - the economics still don't make sense because there are few (if any) places in which the cost of delivered electricity is cheaper per BTU than natural gas or Propane. And tradesmen are not as well trained and regulated as they are over there. It's quite common for regular people to have more experience and do a better job than many tradesmen that show up to out homes these days. Sad and concerning - but true.
Yardbird - strictly speaking, your meter is undersized, but......... Your Rinnai will modulate the gas usage depending on the incoming water temp and the demand called for. So in the summer if you're just running a bath faucet, it's not going to use many BTU's and you'll be more than fine. In the wintertime, well...........could be a problem. You incoming water temp. is much lower than mine in GA and will require more BTUs to heat to hot. If your temps are realllllllly cold and your furnace is running full tilt and you turn on a tub filler - your system will likely be starved and either the furncace or heater will suffer depending on the home's piping layout. Turn on a gas cooktop or oven at the same time and things get worse. Think Thanksgiving.
oberlin1 gave solid advice - call your gas provider. Their engineers will help you calculate your demand needs and will provide a new meter for you. Go bigger than you think you need because you/others may upgrade to a bigger or second unit, add a pro cooktop, a kiln, forge, patio heater, BBQ, ect.......... Better to have the capacity and not use it than to need it and not have it.
et al - For those that care, these things are not silent. There is a fan that runs during operation and while it's not what I'd call loud or noisy - it is audible. And depending on your mounting location, and hookups you may get resonance into the building structure.
There are/used to be apps from the CSST pipe co.'s that will help you size piping systems.
Rinnai now comes with a flush kit as standard. If your heater doesn't have one GET ONE. Plumbers around here will not install a unit without one, and even if they did - it's poor economy to not get one.
If building new or doing a heavy remodel, I recommend locating the water heater in the center of the home and using a manifold to home run all the service lines back to. This cuts down on wasted water while waiting for hot water to arrive and makes it easier to service & remodel during the home's lifespan. Low demand fixtures can be plumbed with 3/8" PEX for even quicker delivery. Though that creates material supply headaches.
Thanks for the response, Xedos. When I received the unit, I was surprised at how much gas they pulled. I guess I was thinking when a furnace is 80,000 BTUs, I did not expect a water heater to need twice as much gas.
When I built my house 30 years ago (DIYer) I was not aware of the water manifolds. I like that idea. When I was building, a contractor was building a house next to mine and had just finished another house with PVC inlet plumbing. The city sent a water surge through the lines, and it blew his plumbing apart inside his finished walls. For that reason I used copper grade L and did not worry about the cost.
DIYers are like contractors. Some are good, some are cheap. Some DIYers cut corners, then some overthink everything. I could not build for a living, because I would starve as I overbuild. But I enjoy the process.
When I built my house 30 years ago (DIYer) I was not aware of the water manifolds. I like that idea. When I was building, a contractor was building a house next to mine and had just finished another house with PVC inlet plumbing. The city sent a water surge through the lines, and it blew his plumbing apart inside his finished walls. For that reason I used copper grade L and did not worry about the cost.
DIYers are like contractors. Some are good, some are cheap. Some DIYers cut corners, then some overthink everything. I could not build for a living, because I would starve as I overbuild. But I enjoy the process.
Cheese
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Yardbird said:
FWIW...I substantially agree with xedos. However, I will disagree with his supposition that the Rinnai is noisy...it is not. The Bosch and the Rheem units are more of an issue.
The water manifolds you refer to were not available 30 years ago...not 20 years ago...maybe not even 15 years ago...this technology is continuing to progress at a steady rate and the prices are being steadily driven down.
When I first installed the Rinnai, I could not purchase a unit in Minnesota from any one, and if I wanted to install one I was forced to have to have it professionally installed. At the time the cost of the unit was $2000 and the cost of the installation was $3500 which was the minimum bid, open to further increases depending upon the install.
I found a distributor in Texas that warehoused the Rinnai water heaters and all of the Rinnai parts and offered 2-day delivery service. Good people...as I installed the Rinnai I learned the process and I also ran out of parts which meant that their 2 day delivery service was golden.
It's been installed for 11 years and I'd never go back to a tank type water heater.
thanks Cheese, although that Cheese handle sounds more Wisconsin than Minn. I already have the pipe resized (have the hard stuff done) to 1" but do need a larger volume meter as that 175 will not cut it.
It is kinda like electrical work, my box was 200A with 40 spaces so i thought I would have plenty. But then I dedicate one outlet to the refrigerator, one to the microwave, run a 240 to the garage for a compressor, and pretty soon I am running out of spaces. I checked to see if I could use the double mini breakers, but my box does not accept them, so may have to add another supplemental box. I did run phone jacks to every room when building but that quickly became out-graded like the carrier pigeon.
It is kinda like electrical work, my box was 200A with 40 spaces so i thought I would have plenty. But then I dedicate one outlet to the refrigerator, one to the microwave, run a 240 to the garage for a compressor, and pretty soon I am running out of spaces. I checked to see if I could use the double mini breakers, but my box does not accept them, so may have to add another supplemental box. I did run phone jacks to every room when building but that quickly became out-graded like the carrier pigeon.
Michael Kellough
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Cheese said:
Have a picture or link to these new dangled manifolds?
Coen said:
That really means nothing as probably 99.999999% of installations are serviced or installed by a certified installer so obviously that would account for the vast majority of deaths. No question that homeowners will dabble with electricity, however very few people mess with gas or propane.
Cheese
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Michael Kellough said:
Sioux Chief offers the manifolds in various sizes & configurations.
https://www.siouxchief.com/products/supply/powerpex-systems/astm-f1960/manifolds
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Here's the traditional method of plumbing fixtures vs the home run & hybrid methods, both of which use manifolds.
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Attachments
mino
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My take here is to avoid the "Home Run" setup. It looks nice, looks maintainable, but it can have huge problems with cold water sanitation as it is nigh on impossible to ensure cold water stays cold in pipes going to the less-used outlets.
For cold water, you want to be as close to the trunk&branch as possible. That way you minimise the lenghts of the tubes where the (cold) water stays still at any point in time.
Also, the "last" outlet on the trunk should be something used often/regularly like a bathroom/kitchen sink or a toilet.
For grey water, of water for appliances (Washing machine, toilet) a setup closer to "the home run-for-machines" is better as you want to easily control the outflow and it is good to have one central "appliances" valve which you close when going off for extended period.
For hot water, with on-demand you want an "hot water island" inside the house where the heater is, and as-short-as-possible runs to the main-use hand-washing outlets: To the kitchen and bathroom sinks. Shover can have a longer run as one uses it usually for a longer time.
With hot water from a tank, same setup can be made as with on-demand, but here a much more comfortable setup is a circuit where the water circulates around on a "trunk" circle and then there are short branches to the various outlets. This allow big distances from the heater/tank to the outlets without affecting comfort.
ADD:
People often run hot and cold water "the same" for convenience during build etc. per above, that is not the best of approaches most of time.
It is counter-intuitive but one should insulate the cold (drinking water) pipes MUCH MUCH more than the hot ones need to be insulated. Insufficient insulation on cold pipes can (eventually will) result in bacteria living in the pipes in the still and warm water. Also, for this reason the cold pipes should have a reasonably big diameter (on the trunk part) so that the thermal capacity of the water in the pipes is sufficient to keep them cold for sufficient time aka as mucha s possible. On the other hand, one wants the hot piping as smal diamater as possible to get hot water fast.
For hot pipes, it is "only" about energy efficiency for the most part. That is unless some runs a circuit system at
For cold water, you want to be as close to the trunk&branch as possible. That way you minimise the lenghts of the tubes where the (cold) water stays still at any point in time.
Also, the "last" outlet on the trunk should be something used often/regularly like a bathroom/kitchen sink or a toilet.
For grey water, of water for appliances (Washing machine, toilet) a setup closer to "the home run-for-machines" is better as you want to easily control the outflow and it is good to have one central "appliances" valve which you close when going off for extended period.
For hot water, with on-demand you want an "hot water island" inside the house where the heater is, and as-short-as-possible runs to the main-use hand-washing outlets: To the kitchen and bathroom sinks. Shover can have a longer run as one uses it usually for a longer time.
With hot water from a tank, same setup can be made as with on-demand, but here a much more comfortable setup is a circuit where the water circulates around on a "trunk" circle and then there are short branches to the various outlets. This allow big distances from the heater/tank to the outlets without affecting comfort.
ADD:
People often run hot and cold water "the same" for convenience during build etc. per above, that is not the best of approaches most of time.
It is counter-intuitive but one should insulate the cold (drinking water) pipes MUCH MUCH more than the hot ones need to be insulated. Insufficient insulation on cold pipes can (eventually will) result in bacteria living in the pipes in the still and warm water. Also, for this reason the cold pipes should have a reasonably big diameter (on the trunk part) so that the thermal capacity of the water in the pipes is sufficient to keep them cold for sufficient time aka as mucha s possible. On the other hand, one wants the hot piping as smal diamater as possible to get hot water fast.
For hot pipes, it is "only" about energy efficiency for the most part. That is unless some runs a circuit system at
JimH2 said:
I don't even know if official stats exist, but it's probably closer to 95...
Dutch law may now prohibit installation of gas burning heaters by private consumers, but European law still makes sure anyone can buy them. All the DIY stores also carry the piping etc.
Anyway, it's just a replacement market in this country now. New builds are with district heating or heat pump.
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