Anyone know how to top up boiler with this set up?

Wheety

The last time we had the boiler serviced the plumber showed me how to top up the boiler. He said I just needed to turn the knob on the valve on the pipe behind the boiler. I've tired this and nothing happens. Did he forget to tell me part of the process? Like maybe I need to open another valve somewhere?


We're due another service soon and I'll get them to show me again but at the moment the pressure is at 0.


This is the valve



These are the pipes going into the boiler. The pipe the valve is connected to is the second from the right with the magnetic filter. I saw videos of these being cleaned as a DIY job, I haven't cleaned it and it's in over a year. Should I attempt it or leave it for the plumber?



This is the view from under the boiler. That's the pipe with the bit of blue on it. There's no lever that I can see. I don't really want to mess with something in there unless you can see something that would be an easy fix.

Wearb

Did you open that blue/grey knob on that valve?

Wheety

Wearb wrote: »

Did you open that blue/grey knob on that valve?

Yeah nothing happens. I'm sure it worked before so I'm wondering if something else is not open or of there's an issue with the pump.

The pump does work when we use the hot water and the water is heated by the boiler (combi) but doesn't seem to pump to the boiler to up the pressure. I'm not sure if we're damaging the boiler using it at 0.

Wearb

Check for any closed valves upstream of that valve

Is that braided pipe part of that circuit?

kerdiff

Is there a pressure gauge close to the boiler itself.

Wheety

Wearb wrote: »

Check for any closed valves upstream of that valve

Is that braided pipe part of that circuit?

I'll check all other valves tomorrow. Baby is asleep now :rolleyes:

Yeah the braided pipe comes from the cold water tank to the pump and then there's another coming from the pump. I'll take more pictures tomorrow.

Would the expansion tank cause this and is it DIYable?

Wheety

kerdiff wrote: »

Is there a pressure gauge close to the boiler itself.

There's one on the boiler and the one on that valve in the picture. It's the same pressure on both.

Lenar3556

I’ve found those automatic filling valves are inclined to stick shut and not let water through. Sometimes a sharp tap of a wrench can free them.

Boiler in an attic - is that common?

Lenar3556

Lenar3556 wrote: »

I’ve found those automatic filling valves are inclined to stick shut and not let water through. Sometimes a sharp tap of a wrench can free them.

Boiler in an attic - is that common?

Boilers can be fitted in attics as long as there is the correct access, flooring and lighting but having the boiler as the highest point of a heating system can have it’s own problems.

Any air in the system will end up in the boiler, the pipework should be designed to allow the air to leave the system before reaching the boiler because the auto air release in the boiler is not designed to pass large amounts of air and is often closed which can lead to the boiler being damaged.

Auto fillers on a heating system are only there to mask a leak on your heating system, not dealing with the leak can rot your boiler and radiators over time, i am told the average lifespan of a boiler in Dublin is 6 years due to contaminated heating systems certainly more gas boilers are sold per head of population than other countries.

Wheety

I had a good look around and none of the valves before the auto fill valve are closed.

Can anyone recommend a good plumber in Dublin (D20) for a boiler service? I think this can only be by PM? Would I be better off getting the auto fill valve replaced with a hose? The boiler is just inside the attic door so access is not an issue.

John.G

If you think that you have pressure on the upstream side (right hand side) of the auto fill valve then remove the black cover on the top and you should see a adjusting screw, turn this slowly clockwise and see if the pressure starts to rise.

Wheety

John.G wrote: »

If you think that you have pressure on the upstream side (right hand side) of the auto fill valve then remove the black cover on the top and you should see a adjusting screw, turn this slowly clockwise and see if the pressure starts to rise.

It took a good amount of turning but seems to be filling in short bursts going by the guage on the auto fill valve. Not sure if I should turn it more?

John.G

The short bursts might be that domestic water pump starting&stopping, open a tap somewhere to get the pump to run continuously and then adjust the screw to give a final pressure of 1.3/1.5 bar. (cold boiler if possible) then SHUT off the (blue) valve on the bottom of the auto fill and you can top up as necessary and also monitor any leaks as you now will have that auto fill function shut off.

Wearb

Wheety wrote: »

It took a good amount of turning but seems to be filling in short bursts going by the guage on the auto fill valve. Not sure if I should turn it more?

Those short bursts could be the safety valve opening and closing?

John.G

That's true, although one would think that that would be reflected in the pressure gauge reading 3 bar but could be faulty, perhaps it would be better to unscrew the adjustment back, get the pump running and then slowly screw down the adjusting screw to get 1.3/1.5 bar then shut off the underneath valve.
I assume that pump is a domestic water pump??.

Also check Boiler pressure gauge.

Wheety

John.G wrote: »

That's true, although one would think that that would be reflected in the pressure gauge reading 3 bar but could be faulty, perhaps it would be better to unscrew the adjustment back, get the pump running and then slowly screw down the adjusting screw to get 1.3/1.5 bar then shut off the underneath valve.
I assume that pump is a domestic water pump??.

Yes, it's a domestic water pump.

The gauge on the boiler was reading the same as the one on the auto filling valve. Would both have to be faulty if it were an issue?

I used the method you described and eventually got the pressure to 1 while it was cold. It's in the green so I'm happy enough with that. It took a long time though. That screw at the top, does that control the pressure? If it was tightened completely would it be 3 bar? The cap said 1.5 bar but I don’t know if that’s a suggestion or the max for that valve?

I closed the blue/grey knob on the bottom of the valve so hopefully it won’t keep topping up?

I have a boiler service booked in but it’s good to have the heating back for now. Baby’s room was around 17.5 last night.

Thanks for the help everyone. Heating is on boost at the moment, just to take the cold feeling out. Heating hasn’t been on in months.

John.G

I'd say you are back in business. Just make a note of the final pressure when the system has fully heated up.
The auto fill valve is just a fancy name for a pressure reducing valve or PRV, not to be confused with a boiler safety valve also known as a PRV.
If you continue to screw it down then it will rise (almost) to the upstream pressure, the reason for setting it to 1.5 bar is as follows...normally an expansion vessel is pumped up with air or nitrogen to 1.0 bar with no pressure on the water side, this is known as the pre charge pressure, the filling (water side) valve is then opened until the pressure on the water side reads 1.5 bar, it will also then be 1.5 bar at the air end, this is known as the filling pressure and will, depending on the E.vessel volume give a water reserve in the expansion vessel of ~ 2 litres to make up for any very slight leakages or air release and means that you don't have to top up the system frequently, once a year or so would be fairly normal. As the boiler and system heats up, the hot water expands and the final pressure should be somewhere around 2 to 2.25 bar, if it goes higher it means that the expansion vessel has failed or the precharge pressure has leaked out and is full of water and the boiler safety valve will lift at 3 bar when the water heats up.

The auto fill function will operate as intended at 1.5 bar (if set to this and left open) but as stated above masks any leakages or expansion vessel failure and eventually lead to corrosion/sludge.
A auto fill valve is not required and can be replaced with a normal valve but plumbers find the auto fill very handy when filling/venting systems without having to open/shut the manual filling valve frequently but it should then be shut off.