The bed is stuck with head up can I manually lower the bed

Category moved from Sewing Machines, to one of the Adjustable bed categories.

You need a bed mechanic. If it clicks, that is the relay, but the motor isn't working.

Contact the maker for the nearest service centre. One of your motors isn't working. There are three, 'head up and down', 'foot up and down', and 'bed raise and lower'.

you can google that.

Here is an example of a Tempurpedic electric bed. Depending on your preference to find a cure or to just woke a band aid to give temporary results. On the first picture you see the screen lever attached to frame rail to raise and lower the head. If you remove the cotter pin and push out the connecting pin, you will be able to detach the motor drive system to lower the head for sleeping. On the other hand, the second picture shows the motor assembly. If you can detach it vs trying repair it in an awkward position, you can open the casing to check the screw drive that extend the shaft that you just detected. While there, check the wiring and plug connection to make sure everything is solid. If you have an assistant and a multimeter, you could also check to verify you have voltage, which should be 120VAC, when the switch is being pushed to raise as well as lower. Maybe check the plug and power before disconnecting anything, just in case.

Only if you can get to the motor and take off the cover and get a spanner or socket and rotate it till the bed lowers if possible but it can be dangerous

Erratic thread!

Had same problem with my husbands moms bed. Found out that it ended up being a stripped plastic piece that the screw uses to raise and lower the bed. Because its stripped the screws don't have anything to grip on again to raise or lower bed. Piece needs replacing, but not sure where to get them.

The problem you are describing happens quite often and there are several solutions.
1. The manufacturer sometimes supplies a manual crank that fits in the end of the motor to manually turn the motor and lower the bed. This crank is usually lost or misplaced (look for it on the bed frame). With the weight of the mattress and person off of the head you may be able to use a pair of pliers or other tool to carefully turn the motor shaft.
2. There is a bolt and nut at the end of the head motor shaft or a hitch pin and bolt. Remove this bolt at the end of the motor shaft where it attaches to the head frame and the head frame will drop to level.
3. Fixing the hand control usually involves taking the two halves apart and bypassing the push-button switch by shorting across the head down switch. This is the best way to diagnose a bad hand control. This is the most difficult solution for the average end user. You ultimately will purchase a new hand control anyway so this may be a viable solution. The hand control gets the most use and abuse and is usually the faulty part.
You may have a bad relay on the junction box control board where all the motors and hand control are plugged in. If the motor runs in one direction, the motor is OK. If you have the micro-switch style 6 button switch hand control you may be able to clean the switches by spraying contact cleaner is the switches and pushing them several times. Check the hand control plug for bent or bad pins at the control board junction box. The hand control pendant runs about $100 and the junction box controller is about $400. Hope this helps.