I have a manufactured home on a well system with storage tanks underneath. Currently I am running a 1/2hp Wayne pump with a CSV set st 40psi. I am looking at a rinnai tankless with PVC venting but the manual states that it needs 60-80psi for optimal performance and 50psi minimum. Would it even work with 40psi? The pressure switch is set to 30/50. Thanks!
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I was surprised at this. I guess maybe there has been a boiling or cavitation problem.
Whether your pump can provide more pressure, depends on the pump. If it is a submersible (down the well), it is more likely that it can.
The CSV, pressure switch, and the pressure tank can all accommodate a higher pressure. But can the pump do it?
Whether your pump can provide more pressure, depends on the pump. If it is a submersible (down the well), it is more likely that it can.
The CSV, pressure switch, and the pressure tank can all accommodate a higher pressure. But can the pump do it?
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Most manufacturers will specify a minimum operating pressure for the model. For most vendors it can still work without flash-boil at 20 psi, but not necessarily at 15 psi. If there is no specified minimum in the manual, call Rinnai.
I am not sure if the pump can or not. I bought the house last August and it had a 1/2hp county line all in one setup on it so I decided to go this route instead.
The PDF on lowes page that I have read shows a 50psi minimum for it. I cannot get rinnai to respond to see if a 10psi difference will be an issue. My issue is for the proper water heating tank is about the same cost as going tankless. I am on LP as well so tankless I am hoping would also save me $$.
The PDF on lowes page that I have read shows a 50psi minimum for it. I cannot get rinnai to respond to see if a 10psi difference will be an issue. My issue is for the proper water heating tank is about the same cost as going tankless. I am on LP as well so tankless I am hoping would also save me $$.
http://pdf.lowes.com/dimensionsguides/766156008160_meas.pdf says
Minimum/Maximum Water Supply Pressure: 15 - 150 PSI
(50 PSI or above is recommended for maximum flow)
(50 PSI or above is recommended for maximum flow)
That manual? I can't see what manual you are referring to. You forgot to put in the URL.
https://www.questargas.com/ForEmployees/qgcOperationsTraining/Water Heaters/Rinnai_REU V2520 to V2532.pdf
See page 2 of that manual.
I have never touched one of these.
Note that in picking out such a thing, don't look at a single GPM. The GPM that you can use in practice will depend on how much temperature rise you are asking it to do. So make sure that what you pick can raise the water temperature by an appropriate amount at 3 GPM.
I apologize for that.
http://pdf.lowes.com/installationguides/766156008290_install.pdf
That is the manual I am looking at. $799 manufactured home approved with LP and PVC venting and intake.
I am not sure I would pay 1500 for it rather than just buy a new tank. Something within a couple hundred would be worth it. I need a direct vent hud approved water heater tank style in order for it to be correct and I've seen those from 800-1000
http://pdf.lowes.com/installationguides/766156008290_install.pdf
That is the manual I am looking at. $799 manufactured home approved with LP and PVC venting and intake.
I am not sure I would pay 1500 for it rather than just buy a new tank. Something within a couple hundred would be worth it. I need a direct vent hud approved water heater tank style in order for it to be correct and I've seen those from 800-1000
Jadnashua
Retired Defense Industry Engineer xxx
A tankless system tends to have a moderate amount of internal friction, so not starting out with 50psi, may result in the outlet pressure being lower than you desire.
If you have hard water from your well, you really will want to also install a softener. The burner gets extremely hot in there so that the water can get hot enough while it flies by to be useful...thus causing mineral deposits inside of the heat exchanger. After awhile, worst case, it plugs it up, before that, it becomes much less efficient. Depending on use and how hard your water is, you would want at least an annual demineralization, and it could be more frequently. If you can't do that yourself, that will add significantly to the maintenance costs. While a tank-type WH will have some mineral deposits accumulate as well, you often can flush them out, but even if you don't, it tends to work until it dies - much longer than the demineralization required on a tankless. Plus, you can get parts or a replacement for a tank nearly anytime, anywhere, which may not be possible with the tankless. The home centers are open 7-days a week most places, and while more expensive, any plumber can replace a tank after hours or on the weekend...that may not be possible with a tankless system.
Depending on how deep your well is, year-round, the incoming water could be quite cold. Those volume specs are based on the incoming water being a particular temperature...colder water in, colder water out, or, your acceptable output may need to be throttled back to limit the volume so it can get hot enough along the way.
A quality tank, well insulated is much better than they used to be for standby losses. The actual cost to heat water a specific amount is the same less the burner efficiency discrepancy (depends, that may or may not be a lot), the differences in standby losses won't be. Regardless, you need x amount of BTUs to heat y amount of water, however you heat it. Efficiency, which includes burner and then the standby costs are what differentiate any of the methods.
If the thing will be outside, it will need to have freeze protection either built-in, or you'll have to ensure it can't freeze somehow.
If you have hard water from your well, you really will want to also install a softener. The burner gets extremely hot in there so that the water can get hot enough while it flies by to be useful...thus causing mineral deposits inside of the heat exchanger. After awhile, worst case, it plugs it up, before that, it becomes much less efficient. Depending on use and how hard your water is, you would want at least an annual demineralization, and it could be more frequently. If you can't do that yourself, that will add significantly to the maintenance costs. While a tank-type WH will have some mineral deposits accumulate as well, you often can flush them out, but even if you don't, it tends to work until it dies - much longer than the demineralization required on a tankless. Plus, you can get parts or a replacement for a tank nearly anytime, anywhere, which may not be possible with the tankless. The home centers are open 7-days a week most places, and while more expensive, any plumber can replace a tank after hours or on the weekend...that may not be possible with a tankless system.
Depending on how deep your well is, year-round, the incoming water could be quite cold. Those volume specs are based on the incoming water being a particular temperature...colder water in, colder water out, or, your acceptable output may need to be throttled back to limit the volume so it can get hot enough along the way.
A quality tank, well insulated is much better than they used to be for standby losses. The actual cost to heat water a specific amount is the same less the burner efficiency discrepancy (depends, that may or may not be a lot), the differences in standby losses won't be. Regardless, you need x amount of BTUs to heat y amount of water, however you heat it. Efficiency, which includes burner and then the standby costs are what differentiate any of the methods.
If the thing will be outside, it will need to have freeze protection either built-in, or you'll have to ensure it can't freeze somehow.
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