Hi, lets see if we can get you sorted in the shortest possible time. Can you get to the balltap in the loft and see whether the float has stuck up in the air?
The only single hot water tap in the house (bath tap) is running normally with hot water. All the other taps are mixers single type so you move lever from left to right to switch from hot to cold. It is all of these taps where no water comes in the hot side. The shower has no water coming either. Should I still try the balltap in the loft or does this suggest something different?
Ok - I have two tanks in the loft, both ball floats are on top of water not up in air. Smaller of tanks has one pipe out of bottom. Large tank (very large, size of big bath) has 3. We also have a large separate hotwater tank (very large almost 6ft tall) in landing that has 2 pipes out, one from very bottom and one from 1/3 of way up. We have a pump in there too I think. (Only been in house a month so still finding my way around things.)
The cylinder has 3 pipes in total, the one out the top as you say is the hot water draw and the 2 into the side, one is on side almost at very bottom and one is on side about 1/3 way up tank. No name on cylinder itself, covered in solid foam, but the electric emersion element has the following details, Backer 3KW 240v type 336 and the control panel for the hotwater and central heating is honeywell.
I have a standard mixer tap in the garage yes, two taps one flow pipe, the kitchen mixer is single tap move lever from left or right to control temperature and up or down on /off. Also just spotted that the only hot working is in bath and the bath has a boosted hot water pipe marked up with the cylinder so all hot not boosted are not working but boosted is, does that still sound like an air lock?
Yes. Can you find a mixer tap, put your palm firmly over the spout, turn on the hot tap and then whilst holding quite tightly over the spout - crack open the cold tap slightly. You should hear a rushing noise as the cold water goes past you hand and up the hot pipework. If this is happening and you are not getting wet briefly open the cold tap fully for a couple of seconds and then turn both taps off. Go to the lowest tap point and open the hot tap, you should get a trickle then a gurgling noise and then the water should flow. If it does not work first time try again. If it doesn't work on that tap go and try another tap a couple of times. If this does not work them come back to me and we can try a different way.
I tried on a few taps now, the hot flows for a bit but then stops, I think it is just running what I have sent back up the hot pipe from the cold but not engaging the tank. I have tried several times on 3 different taps.
You may have taps that don't actually mix water in the spout. The next best option is to look under your kitchen sink and see if you have a hot and a cold washing machine tap. If you have to take the cold end off your washing machine and connect it to the hot one. Turn on the hot and then slowly open the cold. If there are no leaks turn it on full and count to ten. This should clear it. You need to fill all the hot pipework and remove the air for this to work completely - otherwise you just get back what you have just put in and it doesn't pull from the tank and cistern. It may take a couple of attempts.