Not enough heat at the front house part far away from the heat boiler. The front house part had baseboard install but with the heat pipe through back of the house first, I am guessing that the heat energy is losing to the atmosphere before reaching the front house part.
What are some possible major reasons aside from mine that making the problem persist? Is it just because that heating system power isn't enough. I am sure that heat pipes aren't leaking.
It is a water heat using gas.
Notes: 1) Hot water heating 2) steel finned tube 3) It is controlled by one thermostat throughout the first floor(one unit on first floor but as large as the two combine in the second floor); two units on the second floor had its own boiler and separate thermostats respectively (so three boiler and three thermostats total) 4) Three Separate boiler is used in different units and only one pump is being used for first floor