Fixing items during Chol Hamoed:
- The general rule:
In general, it is forbidden to fix items in a professional way during Chol Hamoed. This applies even if it is needed for the sake of the Moed. However, it is permitted to perform amateur fixing jobs on Chol Hamoed if it is being done for the sake of the Moed. Professional fixing jobs are forbidden to be done even for the sake of the Moed, unless it needs to be done for the sake of preventing a monetary loss. Likewise, it may be fixed even professionally if lack of doing so poses a danger. Likewise, it may be fixed even in a professional way if it is needed for the sake of making food during the Moed.
- One may knock a nail into a wall on Chol Hamoed for the sake of hanging a picture, if one will benefit from the hung picture on Chol Hamoed. The same applies to any screw or nail, that it may be banged, or screwed in, if the item is needed to be used during the Moed.
- One may attach a Mezuzah onto a door on Chol Hamoed.
- Electrical appliances that are needed to make food [i.e. an oven or mixer] may be fixed even in a professional way for the sake of making food during the Moed.
- Fan, heater, air conditioner: May be fixed even in a professional way if the heat or cold is causing one pain.
 See Michaber 540:1-8; Piskeiy Teshuvos 540:1-5; Chol Hamoed Kehilchaso 8:1-3, 19, 50-56
 See Michaber ibid; Levushei Serud ibid
 Levushei Serud 540; M”B 540:1
 See Michaber 540:5 regarding an amateur feeding bowl for animals; 540:6 regarding building an amateur bed; M”A 540:7 that only Maaseh Uman is forbidden to be fixed even if it is Tzoreich Hamoed, although Maaseh Hedyot may always be fixed for Tzoreich Hamoed; Maggid Mishneh 8:7 in name of Ramban; Chayeh Adam 113:3; M”B 540:1 and 16; Kaf Hachaim 540:24
 M”A 540:7; Michaber 540:4 regarding fixing a door
 Michaber 540:1
 See Michaber 540:7 permits building oven; Levushei Serud 540 that it is permitted to be done even in a professional way; M”B 540:8; Kaf Hachaim 540:29
 Chol Hamoed Kehilchaso 8:19
 Piskeiy Teshuvos 540:4
 See M”A 540:9; Piskeiy Teshuvos 540:5