Flow and return mixed up

[ianmcd]

Then why would boiler manufacturers go to the trouble they do, to mark up flow an return pipes? The flow pipe will be much hotter than the return, that is the whole purpose of the boiler.

yes of course, and if you had zone valves etc and directional sensitive controls then yes it would make a difference, this is simply a single radiator circuit, the flow is leaving the boiler via the flow pipe, the cooler return is combing back to the boiler via the return as it is simply a circuit, only directionally sensitive TRVs would be affected

 

[Harry Bloomfield]

Then why would boiler manufacturers go to the trouble they do, to mark up flow an return pipes? The flow pipe will be much hotter than the return, that is the whole purpose of the boiler.

The engineer who installed my last boiler, found the new boiler's pipes were the opposite way round to the old one, so he had to struggle a bit to squeeze crossing the pipes in, in the space above the boiler. He wasn't sure he could manage it, the other option would have been to lift the floor boards and swap it in the ceiling above.

 

[FiremanT]

Surely they would have a flow temperature sensor fitted, every boiler I have had since the 80's had one? If it sensed the return in error, it would constantly trip the over- heat stat.

Dear oh Dear.

 

[Harry Bloomfield]

Dear oh Dear.

Go on then, explain if you can?

 

[FiremanT]

How can a combi be connected back to front? Even if you swap F&R the boiler will still be pumping the same way, with regards to its internal components.

Obviously, Efficacy of a Mag Filter will be affected, as will some towel and designer rads, along with older TRV’s. But that is not what you meant.

 

[Harry Bloomfield]

How can a combi be connected back to front? Even if you swap F&R the boiler will still be pumping the same way, with regards to its internal components.

Obviously, Efficacy of a Mag Filter will be affected, as will some towel and designer rads, along with older TRV’s. But that is not what you meant.

A combi with a built in pump, obviously could not - we already covered that ground. We were talking boilers generally.

 

[mattylad]

I once had a combi fitted, when the RGI turned the gas on the boiler started bubbling....
He soon swapped some pipes around then lol

 

[FiremanT]

I once had a combi fitted, when the RGI turned the gas on the boiler started bubbling....
He soon swapped some pipes around then lol

That is your fault for employing the Venemous-anti Punter Man.

 

[FiremanT]

A combi with a built in pump, obviously could not - we already covered that ground. We were talking boilers generally.

Your post was immediately after and in response to the "it is a combi" post

 

[Madrab]

Yup, the original question we were answering at the start was around the OP saying he had a new combi boiler fitted in place of a system boiler.

There isn't any issue with the new boiler, it fine and flows and returns the way it should in respect to it's design, sensors, pump etc ... It's when it was connected to the existing CH radiator circuit the OP reckoned the installer has connected the flow pipe from the boiler to what was the return of the old system.
So the boiler will work as it should, it's just the water is going round the CH system within the house backwards to what it was in the old system and would that cause a problem.

If it was a regular boiler on a W or S plan then the system would need to be piped correctly to the boiler's flow and return