A lot of water coming from the overflow pipe and the boiler vibrating a lot

[platforminc]

Hi All.

I have an ideal logic 24 combi boiler, recently I have noticed that the overflow pipe starts to gush out a lot of water at regular intervals and the boiler is vibrating a lot when the water is being discharged.

I noticed this 2 weeks ago, the pressure refill valve is in the closed position, I noticed the pressure bar was at 3 bar, I then went outside to the valve that allows one to let out the water in the central heating system, then topped it up and stopped at 1.5 bar. Boiler worked fine for a period and now my wife has just called me whilst at work that water is being discharged and the boiler is vibrating.

Does anyone know what could be going wrong before I call out an engineer ?

Thanks in advance.

 

[Madrab]

Sounds like the boiler is over pressurising As long as the filling loop is closed then it's usually down to the Expansion Vessel losing all it's pre-charge pressure, the boiler heats the water, the water expands and that expansion has nowhere to go so the water pressure rises. Once it gets to 3 bar the Pressure Relief Valve Opens - the vibration you are encountering is the valve open and discharges that excess pressure.

I presume once the boiler cools down you have to top it back up again?

 

[mcmoby69]

ring a boiler man, filling loop connected and passing or plate heat exchanger has failed. probably needs a new prv now as well.

 

[Jajodu]

I agree with madrab.

 

[platforminc]

Sounds like the boiler is over pressurising As long as the filling loop is closed then it's usually down to the Expansion Vessel losing all it's pre-charge pressure, the boiler heats the water, the water expands and that expansion has nowhere to go so the water pressure rises. Once it gets to 3 bar the Pressure Relief Valve Opens - the vibration you are encountering is the valve open and discharges that excess pressure.

I presume once the boiler cools down you have to top it back up again?

Thanks for this insight.
I had to rush home last night as it would not stop.

This is what it looks like, and I like to think that the 2 filling valves are in the closed position (the blue and black)

I closed this loop and the whole thing stopped.

 

[Mister Banks]

Do you have a user manual, I dont think you have correctly identified the connections. I think the filling loop is the braided pipe (which should be off unless filling the system), the blue valve is for the cold water feed to the boiler for HW and the black valve is either the flow or the return.

 

[stem]

I think the filling loop is the braided pipe (which should be off unless filling the system), the blue valve is for the cold water feed to the boiler for HW and the black valve is either the flow or the return.

Looks right to me.

 

[ianmcd]

The braided hose is probably from an earlier boiler install

 

[Madrab]

I closed this loop and the whole thing stopped.

View attachment 330244

Looks like you have a legacy filling loop from a previous system and the newer boiler came with an integrated filling loop. The one in the pic with the large braded hose should be left shut off and the hose removed and caps put on the ends on the valves, it's actually looks to be on back to front (check valve should be on the cold water pipe end) but that doesn't matter, it actually helps in this instance. With that one being on, the CH system was constantly filling so the pressure was getting too high and the Pressure Relief Valve (PRV) would be always be lifting, hence the vibration. The leaking pipe looks to be the PRV outlet and if that was leaking it probably wasn't ever watertight but that should have stopped leaking now.

Can quite see the valves on the integrated filling loop top right but both the black and blue handle would be at right angles to the valve when off, make sure it's the correct valves being turned.

 

[platforminc]

Thanks everyone for the input.

Just to be sure, please see the picture below.

I have labelled the valves 1,2,3 and what suprised me today is that I went outside by the drain cock to open it in order to reduce the pressure, I then opened the silver braided valve above this text and the pressure was going up, I didnt use the ones labelled 1,2 and 3. So it made me thinking, are there 2 modes of topping up the pressure ?

Also, for 1,2,3 which one is the valve for topping up pressure, is it 1 and 3 that need to be in the closed position when not topping up the pressure ?

 

[Madrab]

can you give a closer view of the valves on the top right please with the small braided loop included in the pic. If you look at the pic I sent, that is the original integrated fill valve, with 4 handles, 2 at the front that are the filling loop and 2 behind that are the CH return valve and the mains cold inlet valve. Looking at yours though, it looks like it has only one left front valve to fill the system and not 2.

As far as the silver braided loop is concerned then just disconnect the braded hose as it is and the ends of the valves that it came off of, just put the caps on them, not at the other pipe end of the fittings.

 

[platforminc]

can you give a closer view of the valves on the top right please with the small braided loop included in the pic. If you look at the pic I sent, that is the original integrated fill valve, with 4 handles, 2 at the front that are the filling loop and 2 behind that are the CH return valve and the mains cold inlet valve. Looking at yours though, it looks like it has only one left front valve to fill the system and not 2.

As far as the silver braided loop is concerned then just disconnect the braded hose as it is and the ends of the valves that it came off of, just put the caps on them, not at the other pipe end of the fittings.

Please see the attached pictures, when I open the large braided coiled connector the boiler fills. I am not sure if the integral filling loop is open or closed as per the attached pictures.

 

[Madrab]

OK perfect.

The integrated filling loop (small braided/hard pipe) look as if it has only has one valve (can see the top of it as the braided section of the pipe is in the way) - the left front black handle facing downwards. The 2 behind are system valves (L - Blue R - Black) . All the system valve are open when they point upwards towards the base of the boiler.

The fill loop is closed when at right angles to the valve it's part of, as it is at the moment. It's open when it's in line with it. You could let a little more pressure out of the boiler - use a radiator vent - 1.5 bar is really the max you want.

If the system pressure drops slowly then keep an eye on the relief pipe outside and check it isn't still dripping, if it is then the Pressure Relief Valve isn't sitting back down properly and will need replaced.

Also check that when the CH is fully hot that the pressure doesn't rise too high. If the pressure starts @ 1.5 bar you don't want it much over 2 bar, if so then the Expansion Vessel may need looked at. You may also want someone to check inhibitor level as all that excess water may have diluted the system water significantly.

 

[platforminc]

Thanks for the response, there is a magna clean type device at the bottom, can this be opened and then inihitor added, is that the way to do it ?

 

[Madrab]

Yes you could, you would have to empty the mag filter to allow the inhibitor to be added. If you use Fernox, you get their concentrate in a 500mm bottle.
Isolate inlet and outlet, removed and empty the filter, reconnect, fill then top on and open valve then bleed