Ok, 7bar, I'm guessing on the cold. If possible put the gauge on the hot somewhere then run the boiler for hot water then turn the tap off and watch the gauge.
Vokera compact 24 heat exchanger gone - again
- Thread starter sandshoeharry
- Start date
Ok, 7bar, I'm guessing on the cold. If possible put the gauge on the hot somewhere then run the boiler for hot water then turn the tap off and watch the gauge.
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It was the same for both running hot and cold taps separately as I tested both BUT the gauge was on the cold supply (outside tap) which was just the other side of the wall to the kitchen tap used to run water and quickly shut off in test.
I have no way to attach gauge to the hot water supply unfortunately.
As I understand it, any expansion will find it's way to the cold water side anyway as that is all connected and is where the mini expansion vessel should be installed?
I have no way to attach gauge to the hot water supply unfortunately.
As I understand it, any expansion will find it's way to the cold water side anyway as that is all connected and is where the mini expansion vessel should be installed?
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Run the hot tap and turn it off when the boiler is hot then watch the gauge. See if residual heat in the exchanger warming stationary hot water affects the pressure.
Hi @vulcancontinental - I have run the hot tap in the kitchen for 5 mins and then turned it off, and the results were the same as when running the cold tap. Sharp spike to 7 bar and then slowly retracts back to 5 bar over about 7 seconds.
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7 Bar is far too high, fiy a 3.5 Bar reducing valve immediately after your stop cock
A few posters here have a disconnect between reading advice and acting upon it. They seem to have a secret agendaHe won't be told
I thought running hot and turning off would show a bigger rise and emphasise the need to reduce pressure. That boiler's only warranted to 6 bar I recall, when it fails it will not be the boiler's fault.
If you want to play, set up a gauge, turn off the cold to simulate water meter NRV and enable preheat
@vulcancontinental David I remember a job many years ago I went to a warranty call on a linea, seals had popped on the plate and flooded the kitchen, we fitted a reducing valve at the stop cock and fitted a new plate , exact same thing next morning, went back with Eric and we couldnt find anything that could cause it, next morning exact same again, we ended up replacing the boiler, all was fine , old one was sent away to see what was happening but never did hear what the fault was
Thanks everyone. I am not ignoring any advice as I have ordered the following Mini Expansion Vessel (with built in gauge) which arrives on Wednesday:
How to Remove Water Hammer? - YouTube
The chap suggests pressurising to half a bar above your water pressure.
I already have the reducing valve (with speedfit connections) from screwfix as follows:
Reliance Valves Predator Compact 312 PRV 15mm x 15mm | Pressure Reducing Valves | Screwfix.com
I guess all I am struggling with is that IF the mini expansion valve prevents the pressure from spiking to 7 bar and it remains constant at ~5 bar regardless of taps being turned on/off and water heating up etc (which is what I understand its purpose is) then as this is ~1 bar below the max DHW input for the boiler (according to the sticker near the inlet) is there an actual need for the pressure reducing valve. In my mind logically it would suggest not, and if it wasn't in such a difficult location to access I would fit it anyway. I never use the house stop cock and always shut water off at the meter as it is much easier to get to etc.
How to Remove Water Hammer? - YouTube
The chap suggests pressurising to half a bar above your water pressure.
I already have the reducing valve (with speedfit connections) from screwfix as follows:
Reliance Valves Predator Compact 312 PRV 15mm x 15mm | Pressure Reducing Valves | Screwfix.com
I guess all I am struggling with is that IF the mini expansion valve prevents the pressure from spiking to 7 bar and it remains constant at ~5 bar regardless of taps being turned on/off and water heating up etc (which is what I understand its purpose is) then as this is ~1 bar below the max DHW input for the boiler (according to the sticker near the inlet) is there an actual need for the pressure reducing valve. In my mind logically it would suggest not, and if it wasn't in such a difficult location to access I would fit it anyway. I never use the house stop cock and always shut water off at the meter as it is much easier to get to etc.
Fail to see why you are prevaricating. Vulcancontinental works for Vokera and trains like of us who do this everyday and need further knowledge. If VC says to me jump and boiler will be sorted I ask how high. Then you have other responders who do this kind of work every day yet you still fail to heed advice give confusing water hammer with need to lower the working pressure that is knocking out the heat exchangers.
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