Scottscoaled wrote:You need to find out if you are getting extreme heat loss from your underground pex before you sell your boiler. You stated that you insulated it on the outside of the 4" schedule 40. How so? Four feet deep might be an issue also. Find what the temperature differentials are boiler to house and back. Ten degree differential with no load is enough to waste 40 k BTU's more or less. Would make your 115k BTU net boiler a 75k BTU boiler.
It has insulation wrapped around the outside, If i were to do it again I would bury the pipe in spray foam, definitely didnt want the lines that are insulated on the inside because if something happens you cant pull a line out to replace....why would 4ft deep be an issue?
never took temps on the pex coming in the house, I know my mixing valve wont let the house receive anything over 165 to 170 and thats an issue also