problem iflo 3 port valve install? help required please.

[sifly2]

Hi all, I have just replaced an old "smc controller" system with a "Y" plan using an iflo 3 port valve and new pump.
I removed all the old pumps and valves, relay etc and wired as per instructions.

Electrically all seems fine, pump runs, valve moves through positions boiler lights etc and radiators and hot water get hot.

BUT water only seems to pump through system in mid position?...if I set hot water only valve travels across , pump keeps running but after a while boiler cuts out, high temp cutout?

Could I have a faulty valve?

I first thought a partially blocked coil in the cyclinder, but the system was poorly plumbed originally with the vent pipe being between the pump and the cylinder, and with the pump on high, water flows out the vent pipe in mid position, but STOPS when ONLY hot water or heating is selected!

Was going to take valve out tomorrow and have a look, but any ideas as to problem welcomed.

Cheers
Si.

 

[twgas]

Is it still pumping over?
Can you post pics of the pump/valve/cylinder set up?

 

[sifly2]

No pic till tomorrow, but its plumbed like this. http://www.gasman.fsbusiness.co.uk/images/Yppic.jpg
But the vent pipe is where the air bleed is before the cylinder, and the air bleed is above the vertical pump.

The problem is not the pumping over, I'll move the vent to cure that its the lack of flow when in hot water only position!

Cheers

 

[twgas]

I think the pumping over IS your problem, if you move the vent to where it should be your problem will more than likely be solved.

 

[sifly2]

OK thanks, but can you tell me why it only pumps over in mid position ie heating and hot water called, but doesn't pump over when Only hot water is called for? Should it not pump over more? As there is more pressure.

And the boiler cutting out after a short period says lack of flow in hot water only position does it not?

 

[twgas]

You would think so, but it might be down to the whole system configuration.

 

[sifly2]

OK thanks again, just seems strange the pumping over stops as the vent is only 24" downstream of the pump, with only the 3 port and a bleed in between. I can't see why it would stop pumping over when hot water only is selected unless the 3 port is actually closing somehow? The pipe after the valve does seem to cool.

The valve is the right way round and the indicator moves as it should.

 

[sifly2]

Just wondering if I've somehow stupidly mixed up my flow and return pipes, as I can't follow any pipes back to the boiler.

I assumed the layout was the same as this

http://www.gasman.fsbusiness.co.uk/images/contpic.jpg

So I'm wondering now if I didn't take enough care to check the actual pump direction!

I have a photo of the old install so I'll check the pump layout!

Think that might explain the problems as hot water circuit would pump bypassing the boiler.

Will let you know what I find.

 

[sifly2]

Checked old pump direction/ check valve its the same as the new pump!..so back to drawing board!

 

[sifly2]

Checked 3 port all working fine, will correct the vent and see what happens. Wondering if it is just the cylinder coil scaled up causing the boiler to cut out as its not been right for years! And system has only been run at the same time as the heating.

 

[sifly2]

Moved vent /expansion pipe which has stopped pumping over, but as I expected it has not fixed the problem with the hot water circuit!

I can now however hear water trickling through the cylinder coil, so I imagine it is partially blocked which is causing my problems. The cylinder is nearly 50 years old with a mix of steel/copper pipes feeding it so time to replace for a new one I guess.

 

[45yearsagasman]

. The cylinder is nearly 50 years old with a mix of steel/copper pipes feeding it so time to replace for a new one I guess.

I reckon its about 30 years overdue!

 

[sifly2]

OK sounds about right!

Here's a pic of the current Pipework that's accessible in case there are any obvious problems!

Cheers Si.

 

[twgas]

That looks like an ACL drayton valve, if so its connected wrong, and which way is the pump pumping?

 

[sifly2]

Branded iflow, but your right... How did I manage that!! Doh!

Thanks a lot