Vent pipe pitching

Jimjamj

Hi all I turned up the heat out at the oil boiler because when all rads are on and hot water the rads don't get as hot as I'd like but now the open vent is pitching,I have room to raise the vent pipe a good 6 foot,would this stop the pitching.thanks to anyone that can help

shane0007

Check the cold feed & expansion from the f & e tank. It may be blocked. Often seen a mouse or a bat that fell into the tank & got stuck in the outlet.

This will cause both your symptoms.

Jimjamj

Hi thanks for the reply, I have noting stoping flow I opened the feed going to the return of the boiler, it seems to only happen when I turn the temp right up,surely if I raise the vent pipe the 6 foot this will stop pitching.

shane0007

I would still think there may be a blockage. Look into the tank & push a screw driver into the outlet.

Jimjamj

No blockage the vent and feed pipe are getting warm,that's only with boiler on full blast so that's why I was thinking of rising the vent 6 foot over the tank it's a long way for it to push up and over do you think it would work?

shane0007

Was it always doing this or just started recently?

Jimjamj

shane0007 wrote: »

Was it always doing this or just started recently?

Only when I turned up the boiler to its hottest

shane0007

It shouldn't really pitch but it would depend on the pump location & layout of pipework. You could try raising the osvp.

Why have you the boiler set to max. Should generally be at max 75C

Jimjamj

When all rads are on and hot water it's very slow to heat up,raising the vent pipe won't jeopardise safety in any way would it?

shane0007

No but I would be looking deeper into what's going on in the system.

Jimjamj

shane0007 wrote: »

No but I would be looking deeper into what's going on in the system.

Ok thanks for your help,I think myself the feed should be on flow from boiler not return,the expansion tank is working like a rad this way and maybe that extra heat is pushing it up and over

shane0007

If you can have the flow with vent first from the boiler on the flow, then within 150mm from the vent have the feed & expansion & then the pump, you will never have a pitching issue, plus the whole system will be in the desired positive pressure.

Jimjamj

I could do it like that but the pump would be around 20 feet away from feed will that mater? Thanks for taking time to reply

shane0007

That wouldn't matter. The important bit is vent, then feed within 150mm of vent & then pump. But no tees off the vent such as the cylinder coil. It must be continuous to tank. You would then need to put an AAV on the cylinder coil flow to vent air from the coil.

Jimjamj

Oh ok that won't work for me then as the coil is teed off the vent,I could run the feed down 20 feet and tee it in front of the pump

gifted

Would you not consider converting your system from open to a closed system. Get an expansion vessel and remove the F&E tank altogeter.

shane0007

gifted wrote: »

Would you not consider converting your system from open to a closed system. Get an expansion vessel and remove the F&E tank altogeter.

+1
If you have no solid fuel, this would be the best option, more heat too.

nuzzer

turn.pump,down,to,lowest,setting,and,try,,,space,bar,broke,hence,comma's,if,don't,work,just,get,in,a,PLUMBER