Any Central heating Boiler plumbers Help!

[kestral]

If there is anyone out there who knows.

Which way does the pump want fitting for the flow.

Does it pump from A to B or B to A.

It say flow but that means nothing to me. Thanks.

Thanks. Pic attached. Appollo 15/30 boiler/

[B'stard Child]

kestral said:

If there is anyone out there who knows.

Which way does the pump want fitting for the flow.

Does it pump from A to B or B to A.

It say flow but that means nothing to me. Thanks.

Thanks. Pic attached. Appollo 15/30 boiler/

Have you looked at the old pump they normally have an arrow on them (on the casting) Fit new one same as old one

[kestral]

B'stard Child said:

Have you looked at the old pump they normally have an arrow on them (on the casting) Fit new one same as old one

I do not have an old pump to go by.

[Mr Pointy]

If the external piping is to top of the picture then the water in the Flow pipe must be going upwards & the water in the Return pipe coming downwards, so the pump is going B to A if A is connected to the Flow or A to B if A is connected to the Return.

[B'stard Child]

https://www.freeboilermanuals.com/assets/pdf/mysen...

Return is on left - Flow is on the right of the boiler as you look at it according to the manual linked above

Need a better picture of the pipework (above view) because that picture isn't clear

[kestral]

Mr Pointy said:

If the external piping is to top of the picture then the water in the Flow pipe must be going upwards & the water in the Return pipe coming downwards, so the pump is going B to A if A is connected to the Flow or A to B if A is connected to the Return.

A is connected to pipe 2 marked flow but it has that little link pipe to pipe 1 marked return.

B is connected to the tank and the tank has a pipe into the heat exchanger.

[kestral]

B'stard Child said:

https://www.freeboilermanuals.com/assets/pdf/mysen...

Return is on left - Flow is on the right of the boiler as you look at it according to the manual linked above

Need a better picture of the pipework (above view) because that picture isn't clear

From the top.

[B'stard Child]

kestral said:

Mr Pointy said:

If the external piping is to top of the picture then the water in the Flow pipe must be going upwards & the water in the Return pipe coming downwards, so the pump is going B to A if A is connected to the Flow or A to B if A is connected to the Return.

A is connected to pipe 2 marked flow but it has that little link pipe to pipe 1 marked return.

B is connected to the tank and the tank has a pipe into the heat exchanger.

So flow is "B" to "A"

<------------------ That way

[B'stard Child]

kestral said:

B'stard Child said:

https://www.freeboilermanuals.com/assets/pdf/mysen...

Return is on left - Flow is on the right of the boiler as you look at it according to the manual linked above

Need a better picture of the pipework (above view) because that picture isn't clear

From the top.

Thanks

Definately for me flow is "B" to "A"

<------------------ That way

The link pipe on the left between flow and return is probably sided to ensure that the return temps never get below 55 deg C (ie above Condensing Point)

[B'stard Child]

Pipe labelled 3 probably goes to vent pipe above the F&E tank in the loft

[OutInTheShed]

The little link/bypass tube is probably mostly about preventing the boiler air locking.

[B'stard Child]

OutInTheShed said:

The little link/bypass tube is probably mostly about preventing the boiler air locking.

Always up for being educated but how would that help?

[OutInTheShed]

B'stard Child said:

OutInTheShed said:

The little link/bypass tube is probably mostly about preventing the boiler air locking.

Always up for being educated but how would that help?

If there's low flow or air in the system, the link pipe equalises the pressure between flow and return pipes, so you can't get much of a vacuum on the inlet side of the pump. So long as there's some water in the pump, it will circulate and the air will go out the feed pipe or fill/vent via the swirl pot thing.

Without that link, you could possibly get a column of air on the return side and a column of water on the feed side, which the pump won't shift if the pump is working with an air/water mix.

I think non-condensing boilers keep the flue above 55 or whatever by simply not modulating to low levels and not having huge heat exchangers?
Flue temperatures tended to be well above 55C, even before the return started to get warm.

[Lincsls1]

Time for a new boiler?
That thing is what 40 years old?
The combustion case seal doesn't look to clever based on the bits I can see and I'd imagine the emissions could well be very nasty if the burner is the original.
Be careful.

[miroku1]

Amateur hour ptfe on threads not olives .
I’d rip the old piece of junk out and start again