Walls – How to deal with baseboard heating causing problems with a headboard

Other than looking for hidden bleeders (i.e. I have one where the baseboard cover needs to be removed to reveal the bleeder) and bleeding any bleeders that you can find, you may need to swear at whoever put in the new radiators and retrofit bleeders where they are missing.

There is often an automatic bleeder/vent on or just after (in which case it's often on a big cast iron "air separator" that may have an expansion tank hung off its bottom) the boiler, since in theory any dissolved air will be most prone to come out of solution where it's hottest - if that becomes clogged or otherwise inoperable (they don't last overly long) air may migrate elsewhere more than it would if that was working. Sometimes people see a dribble from these and close down the cap on the "tire fill valve" rather than replacing them - which renders them inoperable. I think it's bad practice to depend on that for bleeding the whole system.

Given how anemic circulator pumps are when faced with air bubbles, the only other way of getting that loop clear would be to open the boiler fill and open a drain on that loop, so that the fill water can push the bubble through to the drain - but then you have new water in the system, and some air will come out of that.

The bed frame that you showed at the link (pictured below) is, as you have determined, not at all suitable for having a large headboard attached to it.

This frame is really meant to be used without any surrounding bed adornment or to be used as a mattress support inside of a full surround bed set. The link picture tells it all:

The side panels of this bed set adjoin to the headboard to make a nice solid support.

I would never make a headboard by a bed free standing; especially one that is five feet high. The last thing you would ever want is the thing tipping over on you when you are sleeping in the bed or doing some active activity on or near the bed.

One choice you have is to construct a full bed set. Alternatively you could DIY a support frame that sits directly on the floor and bolts to your head board at one end. The corners of this frame could be joined using pieces of angle iron screwed to the wood. The picture below could give you an idea to work with. Such a floor frame could be made shorter and narrower than the mattress so that it is kind of under the bed. You could even make it out of dimension 2x8 lumber and pad it with a fabric or upholstery material.