Bled radiator and now boiler is losing pressure

need to change thermostat and a thermocouple

If a radiator was taken out and put back in I feel you have air built up in your system. There should; be an air relief valve on each radiator. Get your furnace up to heat and open the valve on each radiator till all the air is out of the lines. If there is air in the system there will be no heat. You do this after the heat is on. As far as the pilot not coming on you could have a bad igniter which may need replacing to get heat.

Did you bleed the air from the pump ? Sounds like a air lock

Are you saying the 3/4 inch valve is dripping and you need to keep topping up the water to maintain the pressure?

If you do this it is "safe" but you will introduce more oxygen in the system with the fresh water.

This oxygen will corrode the radiators and possiblty the boiler heat exchanger depending on how much water you are introducing.

Change the Pressure reflief valve. This is a £10/$ 10 part and will save your system in the long run.

Hi - hope someone can help. I have a VOKERA EXCEL 80SP combi boiler and been without hot water/central heating for two days. The pilot light is on, the fan is on, but boiler not triggering once the hot water tap is turned on.
Hopefully someone come to look at it today but hoping for some advice. Anyone else had this problem?
Thank you.

Pressure is ok? at 1 bar or above
I think on this one there should be a reset button [red] on the left hand top of the casing - or lower the control panel [ phillips screw on each side] and the button is on the left of the base plate. Press this and try the heating.or hot tap
P.S. if you're on a prepayment meter check you have gas.

check the tops of all your radiator valves for bypass if found, easy to repair best of luck

Is your boiler heating your domestic hot water if so i would turn water off to water maker and see if your boiler pressure stays down below 20 psi. If so water maker is bad. The other thing that could cause this problem would be the boiler pump is out.

Hi Leehardcast,

Yes the problems are related. The system is low on water. So now instead of water you have air in radiators which is easily compressed when it heats up. Then pressure loss when it cools down.

Add some water to your system until you have 15lb pressure and bleed out upstairs radiators at the same time.

Please rate this response and Good luck, Phil

Hi tiger650,

I'm Harvey the Master Plumber.

Your problem is: The Alpha SY24 boiler has stopped working. The pressure gauge has dropped, you need to know how to re pressurise the system once the radiators have been bled

Every hydronic heating system is required to have a presure regulator. Most guys call it a feeder valve. Every one I've installed or worked on had one. It's job is to keep the water pressure constant by adding water when you release some air without over filling the system. Sounds like it's not working. Some types can be serviced, others cannont so you may have to replace it. If you're not sure what to do it might be prudent to check the Repair Directory for a repairman.

Feel free contact me again!
Please give me a rating here at fixya.com before you sign off
Thank you,
Harvey your Master Plumber