What can be causing my hot water pipes to rattle?

If it's not an air blockage they could be furring up inside. This means that scale from the water is clogging the pipes. Just like our arteries block with cholesterol. This will be a major plumbing job to replace all pipes.

It can still be air but just running the taps will not help otherwise it would just clear in normal use. What you could have is an air lock. Some air can be traped in the system which is compressed and released, this causes the rattle or vibration. It's mainly due to bad design and often where the water system has been modified. One way to try and clear is to run the system backwards. Sounds mad but you attach the cold water system to the hot and back flow it. Take a short hose and join the hot and cold taps in one sink. Turn on both taps gently, the hose will need securing well as the presure is high. Because the cold system is at a highter presure than the hot the cold water will flow up the hot pipes. Don't do it too long as the water has to go someplace and that might not be a good place. A minute should do then remove the hose and run both tapes. And yes I know that you are not suposed to do this but it's worked for me.

This can be common in older homes. As the hot water runs through cold pipes it can cause the vibrations. Additional bracing for the pipes is an option but of course means tearing through the plaster/ dry wall.

There should be water hammer pipes installed at all faucets. You need to shut the water supply to house off, drain the system and open all the faucets to allow air to fill the water hammer pipes. Close the faucets, refill the sysytem. The air trapped in the water hammer pipe acts as a cushion for the vibrations of "water Hammer" .

Your pipes are not properly attached to the walls. As far as slow water if you have galvanized pipes your pipes have a hardwarter build up and need to have the pipes replaced unfortunately.

Call a pro they can fix it for you and I am sure you will be happy, that kind of work is not a big deal.

My hot water pipe did this and all I had to do was go under the sink and where you turn the hot water off at. I just turned it up a little and now my hot water comes out more and does not vibrate. I think the hot pressure built up. Good luck

Take a flexiable hose from a cold tap to a hot tap and turn on both. This forces air out.

could be high water pressure, should be 80 psi or less, could be expansion/contraction of hot water pipes, defective vavle at water heater or not turned on 100%, as for low flow to kitchen,if pipes are steel,they probably have rust build up in them and need replacing

One pigeon to another -

Loose pipes

Worn washer(s) at the taps

Blockage in pipes from corrosion or settlement

Something resting or leaning on pipes...

Heat can make the water pipes to rattle. Try cold water first.