Fromcarolina
New Member
I have a Rinnai RUR199eN which was installed in February. Since installation, I’ve wondered about the apparent low flow rate. I did some testing today.
I have at least 10.5 GPM on the cold side. It may be greater as the only way I had to measure was from two 1/2 hose bibs running at the same time. I’ll test at the Rinnai as soon as the 10 foot 3/4 hose I ordered arrives. However, pressure at the Rinnai would not be affected by anything in the house as it connects to the cold right where the main enters the crawl space.
I find that I only have 4.2 GPM as output flow rate (option 01 of Performance data at the Rinnai). Parameter setting 11 is at B - High. My cold water inlet temp is 61 degrees F at the coldest (performance data option 08). Hot water temp is set on the unit at 120 degrees F.
Having only a 4.2 GPM output flow rate does not make sense. With a set temp of 120 and inlet temp at 61 degrees, the Delta is 59 degrees. Looking at the Delta T chart, I should be getting a flow rate of about 7 GPM which would be satisfactory. Again, looking at the Delta T chart, an output flow rate of 4 GPM relates to a Delta of 95 degrees - meaning for the flow rate I am getting, my inlet temp would have to be closer to 25 degrees. This is a marked discrepancy and ridiculous.
Can anyone offer an explanation for this performance issue?
I have at least 10.5 GPM on the cold side. It may be greater as the only way I had to measure was from two 1/2 hose bibs running at the same time. I’ll test at the Rinnai as soon as the 10 foot 3/4 hose I ordered arrives. However, pressure at the Rinnai would not be affected by anything in the house as it connects to the cold right where the main enters the crawl space.
I find that I only have 4.2 GPM as output flow rate (option 01 of Performance data at the Rinnai). Parameter setting 11 is at B - High. My cold water inlet temp is 61 degrees F at the coldest (performance data option 08). Hot water temp is set on the unit at 120 degrees F.
Having only a 4.2 GPM output flow rate does not make sense. With a set temp of 120 and inlet temp at 61 degrees, the Delta is 59 degrees. Looking at the Delta T chart, I should be getting a flow rate of about 7 GPM which would be satisfactory. Again, looking at the Delta T chart, an output flow rate of 4 GPM relates to a Delta of 95 degrees - meaning for the flow rate I am getting, my inlet temp would have to be closer to 25 degrees. This is a marked discrepancy and ridiculous.
Can anyone offer an explanation for this performance issue?
