Hello,
I posted previously regarding my baseboard heating. It is run by a furnace, fed by a hot water heater. I've had 3 companies out to service the furnace and am at my wits end, so any advice would be appreciated. The work done in the past 2 months is as follows: replaced water regulator, replaced air vent, replaced expansion tank (a result of having to replace the regulator), adjusted pressure (now between 18-20 PSI)and furnace temp. 2 times, bled the pipes at least 3 times. My husband and I are absolutely positive this noise was not present, save normal baseboard noise, last winter.
Thank you so much for your time!
D.K.

I would be looking at the blower that is in the air handler where the coil is for the hot water heat since you mentioned the noise was causing the air ductwork to knock or shake. A loose motor/bad motor bearing/loose cage fan/paper caught in the cage fan and bad isloator mounts can cause the problem you are talking about.

I would also ad that your original statement about baseboard heating run by a furnace and fed by a hot water heater is very confusing to start with since baseboard type heating is not run by a furnace with ductwork unless it is a hybred system and I do not believe you have that.

Does the heat come out into your home from register grills or do you have hot water baseboard heat.

My heat comes out of a baseboard and comes from hot water. Sorry for the confusion - I thought I had described it well, but now see I didn't. Where would the blower/ air handler or coils be?

Where would the blower/ air handler or coils be?

There will not be any in this situation and in a way that is to bad since I can think of nothing else that the other 3 companies that were at your home did not find since they were there in person.

It is possible that the boiler that generates the hot water is not firing correctly or that you have pipe expansion or water hammer but that would be impossible to tell from here.

I believe you when you say you have a knocking/shaking situation but besides pipe expansion/water hammer/or the boiler not firing correctly I am out of ideas.

Water hammer - Wikipedia, the free encyclopedia

Thank you for your input and the reference for a water hammer. The boiler was never checked out, but it's also onlyl about 5 years old. I either need to call on my home warranty again or possibly go through my homeowners insurance.

I either need to call on my home warranty again or possibly go through my homeowners insurance.

The home warranty might work but I do not believe your homeowners insurance has anything to so with boiler service. Good luck

Thanks again. As I suspected, homeowner's insurance said it was a builder issue and they can't help.