Fd fault on Ideal Heat 15

[Sarah80]

Got fd code on Ideal Logic Heat 15. Had two plumbers out and no joy. It’s had a new water flow sensor, flush with sentinel x800 and refurbished grundfos water pump.
Boiler tries to light and water pump power light comes on but goes off immediately and boiler flashes fd again.
It’s heat only so I have no gauges, tank in airing cupboard. Thank you.

 

[ShaunCorbs]

Might be best to wire the pump temporarily to a plug top and let it run for 5 mins then try turning the boiler on etc

 

[Sarah80]

Might be best to wire the pump temporarily to a plug top and let it run for 5 mins then try turning the boiler on etc

Thanks for your reply, do you mean to wire it to plug top whilst it’s connected to pipes or to remove the head & see if it runs?

 

[ShaunCorbs]

Thanks for your reply, do you mean to wire it to plug top whilst it’s connected to pipes or to remove the head & see if it runs?

While connected to everything least you know if it’s the pump or the boiler then

 

[Sarah80]

While connected to everything least you know if it’s the pump or the boiler then

Thank you. We will try that and I’ll come back to you. Appreciate your help. We are so cold!

 

[Sarah80]

Thank you. We will try that and I’ll come back to you. Appreciate your help. We are so cold!

Ok, wired pump in to plug and ran off the mains. Power lights stays on and pump is running. Turned boiler on and same fd code. Any other suggestions? Thank you

 

[Sarah80]

Ok, wired pump in to plug and ran off the mains. Power lights stays on and pump is running. Turned boiler on and same fd code. Any other suggestions? Thank you

Weird this is but if I tap on the fernox filter above boiler the boiler light comes on and when I stop tapping it, the light goes off again! Its had sentinel x800 flushed through but could it still be a blockage?

 

[ShaunCorbs]

I would say pcb or a sensor as the boiler should fire up best to get a heating engineer out to test

 

[Sarah80]

I would say pcb or a sensor as the boiler should fire up best to get a heating engineer out to test

Had two heating engineers out and they can’t pinpoint it! BUT, although its had a flush the pump wasn’t running so I think maybe put the x800 in whilst the pump is running on mains. Would you try that first? It’s had a new water flow sensor.

 

[ShaunCorbs]

Had two heating engineers out and they can’t pinpoint it! BUT, although its had a flush the pump wasn’t running so I think maybe put the x800 in whilst the pump is running on mains. Would you try that first? It’s had a new water flow sensor.

They haven’t done a flush then

 

[Sarah80]

They haven’t done a flush then

Ah right ok then! So the pump has to be running for it to work? Makes sense to me thinking about it! I just told the second plumber what the first one had done so he will have assumed he had the pump running.
Thanks so much, I will get him back and ask him to do a proper flush!!

 

[ShaunCorbs]

Ah right ok then! So the pump has to be running for it to work? Makes sense to me thinking about it! I just told the second plumber what the first one had done so he will have assumed he had the pump running.
Thanks so much, I will get him back and ask him to do a proper flush!!

Unless he power flushed it then he would use a big ish machine connected to the heating system with some rubber hoses but you normally remove the pump and connect there

 

[Sarah80]

Unless he power flushed it then he would use a big ish machine connected to the heating system with some rubber hoses but you normally remove the pump and connect there

No machine, he put a hose on the bottom of the Fernox filter and x800 in the tank up the loft. But because pump won’t work with the boiler he said gravity would push it through. Water was brownish but then went clear. But now I’m thinking this wouldn’t clear the radiators or would it? Looks like it’s come straight from tank in loft, down to pipes in airing cupboard then boiler and straight out again because only gravity pushing it round pipes. I’ve read somewhere about air separator being blocked, do you know if the x800 would clear that if it was? Thanks again for your help.

 

[ShaunCorbs]

No machine, he put a hose on the bottom of the Fernox filter and x800 in the tank up the loft. But because pump won’t work with the boiler he said gravity would push it through. Water was brownish but then went clear. But now I’m thinking this wouldn’t clear the radiators or would it? Looks like it’s come straight from tank in loft, down to pipes in airing cupboard then boiler and straight out again because only gravity pushing it round pipes. I’ve read somewhere about air separator being blocked, do you know if the x800 would clear that if it was? Thanks again for your help.

Yea that wouldn’t work as a flush its basically just draining and refilling the system

And yes sir seps are a common blockage point east to test with a magnet

 

[Sarah80]

Yea that wouldn’t work as a flush its basically just draining and refilling the system

And yes sir seps are a common blockage point east to test with a magnet

Ok, so I’ve taken the magnet out of the fernox filter and when I hold it next to what I believe is the air separator it pulls near the top. If the pump is running with the sentinel x800 flushing through what’s the chances of it unblocking the air separator or do they have to be replaced?
It’s had so much money spent on it now
I’m very grateful for your help, going to get one of these plumbers back and tell them I’ve spoke to a top man that knows his stuff and they need to sort it!

 

[ShaunCorbs]

In my experience they don’t unblock so remove and reinstall a new one or repipe to standard full and vent etc

Both pump valves are open arnt they and tbh would leave x800 flowing for a week then you will require a drain down and refill and then drain down again to remove as much x800 as you can

 

[Sarah80]

In my experience they don’t unblock so remove and reinstall a new one or repipe to standard full and vent etc

Both pump valves are open arnt they and tbh would leave x800 flowing for a week then you will require a drain down and refill and then drain down again to remove as much x800 as you can

Yes the valves are open.
When we tap the pipe attached to the fernox filter the boiler will light and as soon as you stop tapping it goes out again. It’s had so much done to it now but seems as if it’s something so daft if it’s coming on when you tap the pipe.
Any experience of this?
The pipe goes up from the filter up into the airing cupboard and is connected to the air separator.