Have to activate central-heating in order to top up the boiler pressure.

mrcheez

K.Flyer wrote: »

According to the boiler installation manual, on page 10 of the pre-installation section, it shows a standard filling loop on the return pipe, which, it appears, is what your installers have now set up.

Sorry non-plumber here, which pipe is the "return pipe" and filling loop is the curly metal tube right?

btw are you saying that it wasn't set up correctly in the first image I posted up on page 2?

K.Flyer wrote: »

Can you now increase the pressure without turning on the boiler?

Nope, I just retested there now. All rads are fully bled so that's not the issue.

Incidentally when I turn the "valve screw" there isn't the sound of running water like I said last time, more like the sound of a pressure build-up.

K.Flyer wrote: »

W.B. in their both their installation DVD for this boiler, and in the installation manual on page 21, also show the fitting of their own dedicated filling system (charging link assembly) which attaches to the service valves under the boiler. Check to see if one has been fitted, it should be attached linking the furthest right pipe and the one to its left.
(although looking at the pic of the pipes under the boiler there does not appear to be one there)


If the original problem still exists and this filling system has not been fitted, then fitting one may be part of the solution.

Just to be sure, this is the 34CDi Classic you're looking at right?

If that's a required piece of the puzzle then that must be it.

corkgsxr

K.Flyer wrote: »

I think I might know where the problem is... Robbie.G's earlier post got me thinking..


MrCheez has a combi-boiler and inside the boiler is a diverter valve which the default setting will be DHW, which usually means that in this state, (boiler off or C.H. off), the flow to the radiator circuit is closed.
If the flow pipe from the boiler is running straight to the two zone valves without a by-pass and the zone valves are closed, then that's a sealed pipe. Now if the filling loop is connected somewhere along this pipe, then when the filling valve is opened it is only pressurising this section of pipework and it will not have an impact on the pressure gauge in the boiler.
Turning on the boiler, (calling to heat radiators) opens the zone valves and of course moves the diverter valve, fully opening the circuit and allows the gauge to show the true pressure of the system as its being filled.
The solution should be, as Robbie.G said, is to move the filling valve over to the return pipe, as this pipe should still be open back to the pump housing where usually the connection for the pressure gauge is.
So basically the filling loop connection should be on the C.H. return pipe on the boiler side of any zone valves.


(or a slight variation of the above)

I'm sure Iv had fill on both flow and return and it was no difference on Worcesters and filled away no problem.

I'd love a look at this. I'd do it for nothing but I'm cork.

As regards plumbers from same company looking at it waste of time. If they haven't fixed it they either don't know how or know the issue and are trying to circumvent it.

What's the name on the motorised valves

K.Flyer

corkgsxr wrote: »

I'm sure Iv had fill on both flow and return and it was no difference on Worcesters and filled away no problem.

But were they combi units as well, it may depend on which ports close on the diverter valve when in DHW mode and location of zone valves.
Although on the Ariston the filler line links from the mains service valve to the flow service valve??

I'd love a look at this. I'd do it for nothing but I'm cork.

Would prefer to have an up close look at it myself.

As regards plumbers from same company looking at it waste of time. If they haven't fixed it they either don't know how or know the issue and are trying to circumvent it.

Agreed.

corkgsxr

Yep. 80% of what I fit is Worcester combi's

Small few worchester std boilers.
Small few glowworm combi's / std boilers

Robbie.G

It has to be restriction on the return if it was changed to the flow I think it would sort it.
Looking at the pics nothing jumps out though

K.Flyer

mrcheez wrote: »

Sorry non-plumber here, which pipe is the "return pipe" and filling loop is the curly metal tube right?

The return pipe is the pipe that takes the cooler water back from the radiators to the boiler for re-heating.

Yes the filling loop us the flexible steel tube.

btw are you saying that it wasn't set up correctly in the first image I posted up on page 2?

Usually it should not make a difference, but if my theory is or was correct then yes it would have been set up wrong.
Interesting to note that the manual shows the std filling loop and the dedicated filling device both feeding into the return.

Incidentally when I turn the "valve screw" there isn't the sound of running water like I said last time, more like the sound of a pressure build-up.

I am going to "presume" your mains pressure is not particularly strong, thats why you have a breaker tank and a pump on the system. You may now be at the max pressure your mains can give to the system.

Just to be sure, this is the 34CDi Classic you're looking at right?

Yes, the manual is for the 34 CDi.

If that's a required piece of the puzzle then that must be it.

Well the manual does show both options, so it may or may not be essential. But most likely it is the preferred method by the manufacturers as its shown as part of the assembly on the DVD.

K.Flyer

corkgsxr wrote: »

Yep. 80% of what I fit is Worcester combi's

Small few worchester std boilers.
Small few glowworm combi's / std boilers

Do you use the their filling link assembly or just a std loop?

Dtp1979

I think it's time for a boards meet up at mrcheeze's house

K.Flyer

Robbie.G wrote: »

It has to be restriction on the return if it was changed to the flow I think it would sort it.
Looking at the pics nothing jumps out though

From what I make of the pictures, the loop was originally on the flow, and has now been moved over to the return after the mag.

Has the filling loop been replaced yet?


(I'd fit a system pressure guage to help determine pipework pressure, I'd also consider replacing the filling loop and replacing the guage on the boiler)

corkgsxr

Dtp1979 wrote: »

I think it's time for a boards meet up at mrcheeze's house

You bring the beer I'll bring the Jameson

K.Flyer

gary71 wrote: »

Has the filling loop been replaced yet?

I had though of that earlier, but I had hoped the original fitters would have checked it first.

Robbie.G

K.Flyer wrote: »

From what I make of the pictures, the loop was originally on the flow, and has now been moved over to the return after the mag.

Yes but that was directly against the abv
So it would be doing the exact same thing as now.If it was put in before the abv then that would be a different story.
I think they had the same problem as now that why the 318 is capped.

Egass13

corkgsxr wrote: »

You bring the beer I'll bring the Jameson

I'll bring the bible

K.Flyer

K.Flyer wrote: »

I had though of that earlier, but I had hoped the original fitters would have checked it first.

I don't trust nuffink or nobody

corkgsxr

Egass13 wrote: »

I'll bring the bible

But firelighters are Easyer? And a decent blowtorch will negotiate the need for tinder

scudo2

corkgsxr wrote: »

You bring the beer I'll bring the Jameson

10 plumbers on Jameson giving their opinion !


I'll bring the pop corn.


Anyway, back to biz,
Why didn't the auto bypass valve set at 0.5 bar allow pressure to equalise on either side of MV's
Crap valve ?


OR
Filling loop is connected on the wrong side of bypass valve, bypass valve is also one way valve, allowing no water to equalise back into the system ??

corkgsxr

scudo2 wrote: »

10 plumbers on Jameson giving their opinion !


I'll bring the pop corn.


Anyway, back to biz,
Why didn't the auto bypass valve set at 0.5 bar allow pressure to equalise on either side of MV's
Crap valve ?


OR
Filling loop is connected on the wrong side of bypass valve, bypass valve is also one way valve, allowing no water to equalise back into the system ??

Didn't thy try both flow and return?

Any name on those motorised valves

mrcheez

K.Flyer wrote: »

The return pipe is the pipe that takes the cooler water back from the radiators to the boiler for re-heating.

Just so I know, could you identify it in one of the pics please?

e.g. "IMG_5818.jpg, it's the curved pipe to the right of the Magna clean" etc. Thanks!

K.Flyer wrote: »

I am going to "presume" your mains pressure is not particularly strong, thats why you have a breaker tank and a pump on the system. You may now be at the max pressure your mains can give to the system.

Mains pressure is very strong (cold tap in kitchen is nice and strong). Pump is there because I wanted a strong shower (also I wanted the tank moved from attic to outside, so the pressure has to push the water upstairs)

gary71

gary71 wrote: »

Has the filling loop been replaced yet?


(I'd fit a system pressure guage to help determine pipework pressure, I'd also consider replacing the filling loop and replacing the guage on the boiler)

As above

mrcheez

No idea, plumbers don't like to be watched like a hawk when they work so I oblidge!

I'd say it looks the same as the one in the pic on page 2 though

mrcheez

mrcheez wrote: »

No idea, plumbers don't like to be watched like a hawk when they work so I oblidge!

I'd say it looks the same as the one in the pic on page 2 though

It controls the water filling your system so I'll leave it up to you to decide if you want to find out.

mrcheez

Reckon the back-flow valve in the filling loop is stuck, or it's a one-way?

What in the filling loop could be causing the issue?

K.Flyer

mrcheez wrote: »

Just so I know, could you identify it in one of the pics please?

It is the pipe that connects to the furthest right hand service valve under the boiler and appears to (should be) connect to the top of the Magna Filter.

Mains pressure is very strong (cold tap in kitchen is nice and strong). Pump is there because I wanted a strong shower (also I wanted the tank moved from attic to outside, so the pressure has to push the water upstairs)

The mains pressure can only be correctly verified with pressure gauges.

mrcheez

mrcheez wrote: »

Reckon the back-flow valve in the filling loop is stuck, or it's a one-way?

What in the filling loop could be causing the issue?

I'd replace the filling loop as a given if only to rule it out(there is a check valve incorporated in the valve and like any mechanical device can cause problems)

You either have a boiler that doesn't like external filling loops(which i'v never seen)

A filling loop which is defective(which I'd put my money on if I had any:o)

Or the boilers own guage is defective(rare but possible)

My advice is once you have proved the filling loop is pressurising the heating system ask Bosch what is preventing the boiler from filling without the pump.

mrcheez

gary71 wrote: »

I'd replace the filling loop as a given if only to rule it out(there is a check valve incorporated in the valve and like any mechanical device can cause problems)

You either have a boiler that doesn't like external filling loops(which i'v never seen)

A filling loop which is defective(which I'd put my money on if I had any:o)

Or the boilers own guage is defective(rare but possible)

My advice is once you have proved the filling loop is pressurising the heating system ask Bosch what is preventing the boiler from filling without the pump.

The pump doesn't activate when the heating is on, or when topping up the boiler. It only activates when taps are turned on (or toilet flushed).

So when I'm topping up the boiler with the heating on the pump is never active and I'm guessing it doesn't factor?

I'm still not clear why a filling loop would work when the heating is active, but not when heating is off.

K.Flyer

mrcheez wrote: »

...
I'm still not clear why a filling loop would work when the heating is active, but not when heating is off.

Isn't that what the entire thread is about.
That's what has us all scratching our heads.. because we would expect it to fill the system unless there was a fault with it or an error somewhere.

mrcheez

mrcheez wrote: »

The pump doesn't activate when the heating is on, or when topping up the boiler. It only activates when taps are turned on (or toilet flushed).

So when I'm topping up the boiler with the heating on the pump is never active and I'm guessing it doesn't factor?

I'm still not clear why a filling loop would work when the heating is active, but not when heating is off.

Forgive me "pump" as in the boilers own pump, when you run the heating it impacts on the pressure the other side of the filling loop which may allow a defective filling loop to operate.


I like to start at the beginning which in this case is your filling loop.

mrcheez

K.Flyer wrote: »

Isn't that what the entire thread is about.
That's what has us all scratching our heads.. because we would expect it to fill the system unless there was a fault with it or an error somewhere.

nah I mean logically speaking, what inside the filling loop "switches on" when the boiler is active?

Is it maybe to do with pressure "pushing harder" through the filling loop when it's active or something?

mrcheez

gary71 wrote: »

Forgive me "pump" as in the boilers own pump, when you run the heating it impacts on the pressure the other side of the filling loop which may allow a defective filling loop to operate.


I like to start at the beginning which in this case is your filling loop.

ah ok, that probably answers previous question in #90