electric heat in mh

[nita]

please can any one help me our heater is intertherm we live in 16/80 mobile home the sesensor went out and we had it replace and the heating man said that he had to put in a baffle so the inside did not get hot before the work was done it would not get over 64 in the house now the work is done it get up to 70 but the heater run for 2 min then cut off and 5min later it will go on and run 2min then off again it will not run longer than 2min even if you turn up the temperture what do i do