I have a alpha cd32 boiler,and i keep having to top the water up within the boiler,so to get hot water and heating again.i have checked for water leaks and nothing is found,however i did check the outlet pipe to outside and water was inside,im guessing this is where the water is going!!any idea why?!!please p.s when i do get the pressure over 1bar the system is fine until i switch it off.

You need to check with the boiler/system specifications to discover the correct pressure.

An overpressure condition should be dealt with by a safety valve that usually vents to the outside of the building - if it is working correctly. There have been incidents of this external vent freezing causing dangerous pressure to build in the system. I understand a modification is simple and inexpensive but I don't know any details.

Our pressurised system runs at about 2.5 bar hot, or at least it used to do when it was younger...

Combi-boiler-turn hot water tap on/off and the heating stops for ...

singletrackworld.com/.../combi-boiler-turn-hot-water-tap-onoff-and-the-...

Combi-boiler-turn hot water tap on/off and the heating stops for 20secs ... hot watertakes priority over central heating so when you run the hot tap, heating is ... Yeah onmy worcester combi there is a diverter valve - it feeds either the heating or ...

My central heating works but I have no hot water - 24'7 ...

https://www.247homerescue.co.uk/my-central-heating-works-but-i-have-...

Diverter valves switch heat between the hot water and the central heating. When youturn your hot tap on, the diverter valve temporarily shuts off the water supply ...

Does your boiler keep switching itself off? Here's why ...

www.dhs-uk.com/does-your-boiler-keep-switching-itself-off-heres-why/

Jul 7, 2015 - ... Bathroom Suites, - Showers, - Wet Rooms, - Taps and Accessories, Information and ... Low water pressure can cause your boiler to turn itself off. ... boiler is not turning off, you aren't getting the amount of hot water you require. ... If there is air in your central heating system, then your boiler may shut down.

I assume losing pressure through the PR means Pressure Relief Valve (PRV) or temperature pressure (TPR). Open in TPR may mean boiler is overheating/overpressurized. Open in PRV means the Pressure Reducer/Fill Valve in the fill line of the boiler is broken.
House Water Pressure in a home is 30/40 PSI min to 60-80+PSI max.
Boiler PRV/TPR are set at 30 PSI open (SYSTEM PRESSURE) so too high a house water pressure will open the PRV/TPR. Replace the reduction regulator on/in the fill valve assembly

Had this happen to me before, if you have hot water from the boiler going in and out of the boiler mate and the temps are not rising within the hot water means more than likely you may need to remove exchanger and clean sediment off element, basically sediment creates a blanket over the heat source causing poor thermal conductivity. Things to check before removing heat exchanger

- outlet temp of boiler water to aquamate -inlet temp of boiler water to aqua mate= 20-30'F if low then bad thermal transfer or poor water movement
-make sure sensor is reading properly
- get boiler temp higher to speed up thermal gain in water heater

It could be dyslexia, but I think you want to know what may be wrong with your boiler in this case!
This is a VERY old design. The diaphragm is on the water section, this operates a switch to turn ON the pump, and a further device causes the diverter valve to divert boiler water from CH duty to HW duty.
From your description it appears that the boiler is shutting down on internal boiler water temperature (too high), your 'briefly too hot' HW symptom may be caused either by the boiler side of the secondary heat exchanger being blocked/caked in sludge, OR the DHW side of it being scaled. Either way a new or replacement (descaled) secondary heat exchanger MAY inprove things. It's not easy on these old clunk-pots, and EVERY disturbed seal will subsequently leak, so get a good supply of o-rings and fibre seals before you start ("you" being the competant fitter you employ)

I would replace the relief valve or remove it to see if it is plugging up.
Buy some cleaner and run it through if you have not done it in a while.
Do the other anyway.

It doesn,t like your boyfriend

most likely the diverter valve.. when hot tap turned on the movement of the water through the valve operates a diaphragm which pushes a pin/button//switch to tell the boiler to fire up

the problem there a relay stuck or thermostat bring on the pump & you can lower your high limit aquastat!! also the flow valves can bypass hot hot water risers time to put in a seperate water heater domestic coil are not energy efficient !!!! aquastat high limit set @ 180f deg low limit set @ 140f deg!!!
good luck!!! tim

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