Furnace/Air Conditioner System

Can someone tell me if I can safely close a couple of my floor registers, and then close the door to those two rooms in order to keep the main part of my home warmer?
My other home had a heat pump and I was told I could not do this as it was not good for the heat pump.
Thanks in advance.
Corinne

are there any water pipes running thru any of those room walls or ceilings? does your roof snow handling depend on lost heat as with ice concerns at a central downspout that runs thru the center of the home? is there a cold air return in either of these rooms? are there considerations for plants or pets? is there a heated waterbed? if no, then try it out if there will be no damage to the fine furniture or antique books or contents of the rooms. you also might [if outlet circuits are sufficient] place a small electric heater in each room set at say 40 degrees F. this would be available to warm up the rooms along with a 20 inch window fan blowing in some hallway heat if you have a guest.

Great questions, and it looks like I will be OK. Many thanks.
Corinne
buffalobill wrote:
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To the list of considerations, I would add:
Keep in mind you have these closed off registers if you set back the temp for an extended period when you are away. A room with some water pipes may be fine if the rest of the house is at 70 but freeze if you turn the heat down to 45 while you are away on vacation. If you have any concerns about anything freezing in that room, I'd leave the door open when you turn the heat down for an extended period. It's also a good idea to open the doors to cabinets under sinks with water pipes in the exterior wall with the heat set low, for the same reason.

Thanks for taking the time to reply.
I only have two bedrooms that I can close off, and even then, a little air gets through the vents.
I always open them if I am gone, to avoid any freezing problems.
And, I also open cabinets where sinks are underneath.
Many thanks.
Corinne
snipped-for-privacy@optonline.net wrote:
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Corinne wrote:
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Assuming an optimally sized duct system, as a general rule, never close down more than 1/3 of the openings.
hvacrmedic

I see very few properly sized duct systems. 1/2 of the systems I measure only have 1/2 required air flow OR LESS! I would say NO.
Stretch