Potterton profile 100e

[mfgs]

I am having a bit of a nightmare with a Profile 100e. I was called in because it was over heating and kept tripping them stat. A new pump was fitted about 6 months ago. I put my clamps on the flow and return pipes directly above the boiler and the overheat stat was tripping when the flow pipe was at 72-75 degrees, spoke to technical who said it should trip at 95 and to replace the stat. New stat fitted and exactly the same issue.

Then my customer informs me that another plumber was here before and spotted the pump was on the wrong way round and had flipped it. When I checked it, it all seemed fine, pointing away from the boiler and towards to two zone valves. Then I went to check the f and e tank and the cylinder. Feed and vent come off the flow and return to the cylinder like an old gravity set up.

So back to the boiler and a quick look in the manual shows the pipe the pump is on should actually be the return ( the manual shows the flow being the left hand pipe on the boiler and the return the right) but the pump is pumping away from the boiler. The main boiler stat is situated on what should be the flow pipe but with the current set up is now the return. So is it acceptable to swap the pump around to the way it was previously pointing back to the boiler, with the zone valves essentially behind it? Can you zone on the return like that? There is a manual bypass fitted as well.

Sorry for the long post, this one just has me a little confused.

 

[mfgs]

Also just to point out, the boiler was suffering from the over heating problem with the pump facing both ways. So swapping it around may not cure it but hopefully it will help point me in the right direction and give me the ability to check the boiler stat more accurately etc.

 

[gassafe]

When is it overheating? On shut down when the valves shut? Maybe the pump overrun has stopped working?

 

[Leo21]

That's even if there's a pump overrun wired in. Don't these have a pumped and gravity switch on the front panel?
Surely the stat has failed if it's getting that hot? The stat should be clicking off on temperature well before 95!
And it should be fine swapping the pump back, it would put the f and e pipe in a better position with regard to the pump.

 

[mfgs]

It overheats when the pump is still running. The boiler stat isnt shutting it down as currently its on what effectively is now the return and I have about a 13 degree temp difference. The pump is wired in to the boiler, but it overheats before the boiler stat is kicking in.

I'm thinking of swapping the boiler stat and switching the pump around?

 

[Leo21]

It overheats when the pump is still running. The boiler stat isnt shutting it down as currently its on what effectively is now the return and I have about a 13 degree temp difference. The pump is wired in to the boiler, but it overheats before the boiler stat is kicking in.

I'm thinking of swapping the boiler stat and switching the pump around?

That's your problem then, it needs to be reading the flow.

 

[mfgs]

Yeah agreed, but my customer has told me this issue was still happening before the pump was swapped around. So think there must be a secondary problem.

 

[Leo21]

At least the customers aware, so no daft arguments over the fix.

 

[Last Plumber]

Yeah agreed, but my customer has told me this issue was still happening before the pump was swapped around. So think there must be a secondary problem.

If I'm right, the issue existed before the other plumber swapped pump around.
( he was wrong of course). You swapped the overheat but the pump is now pumping the wrong way so the boiler stat/flow sensor is reading the return.

If you put the pump back to how it should be, you may find that the problem is solved !

If not, it's not really your fault that his antics threw you !
So start again after you've explained to the customer.
Ask if there is anything else you might need to know

and whilst you're at it, put those MV's on the right pipe

 

[mfgs]

I don't think the over heat stat was the issue as its tripping at exactly the same temps as before. Until I get back and swap the pump around I don't really know where I stand.
I love and hate jobs like this, I enjoy a challenge but this is just annoying me as I am struggling for time to fit it in. Every time I speak to the customer he gives more info, turns out I am actually the third person to have a look at it. I was originally called because the heating wouldn't come on, swapped the actuator, got that working and then he mentioned this.

 

[AllyBongo]

I'd be looking a re-piping as per MI's, theres an estate near me which has Ideal Classics, all open vents and piped wrongly, if they start drawing air in its usually game over until its piped correctly. Just thinking your fault may not lie with the boiler if the OH stat has been ruled out

 

[kb76]

Can you trace pipework from boiler to cold feed/vent, cylnder coil, pump and zone valves etc. If you can you can determine if it's piped correctly. I came I cross loads of fully pumped open vent systems which are piped incorrectly and must have been drawing in air since day 1. If I can't trace all pipework or looks like it's wrong I generally seal the system, expansion vessel, filling loop and PRV. Dump the header tank and cap open ends. If it's air that's causing the issue job done!

 

[Elgordo]

Repipe it the way it should have been done and be prepared for sludged up sections that won't flush and will need replacing .Be sure to cover yourself well with pricing