I did a search and didn't see anything covering my issue.
I have a 36' Excel Limited Edition, 2012. I've only used the RV a couple times since purchased. I noticed a slight surge when turning on the water, hot or cold. After hearing an occasional thumping from the water lines, I installed a pressure guage on the hot water at the washer hook up. With a starting pressure from the on board pump, pressure builds and maintains ~45 lbs. Low I know since the pump info indicates 55 lbs but that's not the issue. At a pressure of 48 lbs, when the water heats up in the water heater, pressure builds to ~120 lbs. Plumbing is excessive for the pex pipe rated at 100 lbs. Not connected to city water, working off the on board pump but same thing happens when connected to city water. Pressure relief valve at water heater check and confirmed it functions. After talking with Atwood, maker of the hot water heater, they indicated pressure build up would be expected from the expansion of the water heating but couldn't say how much. Has anyone checked their pressure build with a good presssure guage specifically looking for how much pressure builds up when the water in the hot water tank is cold and then turned on to heat to it's maximim temp. The pressure build up I have is way too much so any ideas would help. I'm currently letting the water drip in the bathroom and this relieves the expansion problem but not a fix. I'm have picked up an expansion and am going to do a temporary connection to see if it absorbes the pressure build up but haven't done it yet. Any insight, suggestions, recommendations from anyone is appreciated. Excel to this point hasn't been any help.
Lucky Mike said
04:28 PM Oct 1, 2014
Pex ratings
100PSI @ 180 degrees
160PSI @ 74 Degrees
if your getting high pressure from your HWH I would suggest purging the tank by opening the pressure relief valve to make sure there is an air pocket in the tank....sounds to me like your tank is flooded.
either open the pressure relief valve with the water supply off or Drain the tank and refill.
Normal RV water pressure is 45 pounds....
all pressure readings must be taken from outside at the inlet or at the source not at the faucets
igotjam said
05:39 PM Oct 1, 2014
Have exactly the same condition in my RV. I have a Suburban heater in a 3+ year old RV. It has done the same since new. I use the same remedy as you do (relieve pressure by opening a tap.) If I do nothing the pressure relief valve eventually weeps water soaking the heater connections and running down the outside of my rv.
ND said
10:23 AM Oct 2, 2014
Lucky Mike wrote:
Pex ratings
100PSI @ 180 degrees 160PSI @ 74 Degrees
if your getting high pressure from your HWH I would suggest purging the tank by opening the pressure relief valve to make sure there is an air pocket in the tank....sounds to me like your tank is flooded.
either open the pressure relief valve with the water supply off or Drain the tank and refill.
Normal RV water pressure is 45 pounds....
all pressure readings must be taken from outside at the inlet or at the source not at the faucets
I'm not understanding what difference it would make where the pressure is tested on a closed system such as when you're working off the on board pump. Seems to me, 100 lbs pressure anywhere on the system is too much, could you elaborate?
I'll look closer on the pex in my unit but it clearly states 100 PSI MAX. Didn't see anything on variances based on temp. My home pex does but not the RV.
Alie and Jims Carrilite said
10:33 AM Oct 2, 2014
Do you have an expansion tank on board? A 1 gallon tank would help reduce the rise in pressure due to heat. Are you using good water pressure regulator like a Watts 263? The small inline regulators will let pressure build up over time due to leakage in the orifices.
What is the hot water tank thermostat set to? If its maxed out at 140+ that might be the issue.
-- Edited by Alie and Jims Carrilite on Thursday 2nd of October 2014 10:34:46 AM
I did a search and didn't see anything covering my issue.
I have a 36' Excel Limited Edition, 2012. I've only used the RV a couple times since purchased. I noticed a slight surge when turning on the water, hot or cold. After hearing an occasional thumping from the water lines, I installed a pressure guage on the hot water at the washer hook up. With a starting pressure from the on board pump, pressure builds and maintains ~45 lbs. Low I know since the pump info indicates 55 lbs but that's not the issue. At a pressure of 48 lbs, when the water heats up in the water heater, pressure builds to ~120 lbs. Plumbing is excessive for the pex pipe rated at 100 lbs. Not connected to city water, working off the on board pump but same thing happens when connected to city water. Pressure relief valve at water heater check and confirmed it functions. After talking with Atwood, maker of the hot water heater, they indicated pressure build up would be expected from the expansion of the water heating but couldn't say how much. Has anyone checked their pressure build with a good presssure guage specifically looking for how much pressure builds up when the water in the hot water tank is cold and then turned on to heat to it's maximim temp. The pressure build up I have is way too much so any ideas would help. I'm currently letting the water drip in the bathroom and this relieves the expansion problem but not a fix. I'm have picked up an expansion and am going to do a temporary connection to see if it absorbes the pressure build up but haven't done it yet. Any insight, suggestions, recommendations from anyone is appreciated. Excel to this point hasn't been any help.
100PSI @ 180 degrees
160PSI @ 74 Degrees
if your getting high pressure from your HWH I would suggest purging the tank by opening the pressure relief valve to make sure there is an air pocket in the tank....sounds to me like your tank is flooded.
either open the pressure relief valve with the water supply off or Drain the tank and refill.
Normal RV water pressure is 45 pounds....
all pressure readings must be taken from outside at the inlet or at the source not at the faucets
Do you have an expansion tank on board? A 1 gallon tank would help reduce the rise in pressure due to heat.
Are you using good water pressure regulator like a Watts 263? The small inline regulators will let pressure build up over time due to leakage in the orifices.
What is the hot water tank thermostat set to? If its maxed out at 140+ that might be the issue.
-- Edited by Alie and Jims Carrilite on Thursday 2nd of October 2014 10:34:46 AM