Open Oil/Back boiler system frequent overspill

[Flagstaffview]

2 Storey detached house with Open Vented system Oil + Coal Back boiler stove. The problem is the Oil when it comes on often causes hot water to blow up into the Central Heating Feed thank.

I have talked to another plumber about the issue and he suggested up=sizing the Vent pipes to 28mm and I had already made them go as HIGH as possible in the roof before bending them back towards the tank.

Speed of the Heating Pump is I.

Another Plumber has suggested "capping" the oil system with a stop=end and put a 3=bar safety valve onto the oil boiler - or maybe it would be safer to put a 3 = bar safety valve onto the end of the Vent pipe too!

The problem has arisen due to Upgrading the old Oil boiler to a new Condensing One and the Main Heating pipes from this boiler come into the HoT-water Cylinder at the Floor level 2 rather than entering the house at the ground floor. This means the "Hot water in the Central heating" is taking the ESCAPE route up the VENT rather than working its way around the radiators!

Its my own home! which is not good for my PR! Help

 

[PhoenixServices]

You got the cold feed and vent position correct, plus position of the pump.

 

[Best]

Your first plumber obviously did it wrong & you should insist he sorts it.
What i would like to know is where do the new pipes from the oil boiler join into in the airing cuboard. There will be two 28mm pipes (gravity primaries from back bolier) with vent & feed pipes joined into a coil on the hot cylinder. Your new pumped pipes should NOT be connected to those pipes!! Pumped circuit shouldn't join to gravity circuit. Does your back bolier heat up when oil boiler is on?
If they are correct & connected to the heating pumped circuit, then it should be simple to fix, but requires a heating guy to look at system first.
Where are you in NI? Someone could take a look at it for you.

 

[Flagstaffview]

Your first plumber obviously did it wrong & you should insist he sorts it.
What i would like to know is where do the new pipes from the oil boiler join into in the airing cuboard. There will be two 28mm pipes (gravity primaries from back bolier) with vent & feed pipes joined into a coil on the hot cylinder. Your new pumped pipes should NOT be connected to those pipes!! Pumped circuit shouldn't join to gravity circuit. Does your back bolier heat up when oil boiler is on?
If they are correct & connected to the heating pumped circuit, then it should be simple to fix, but requires a heating guy to look at system first.
Where are you in NI? Someone could take a look at it for you.

posters son here the plumber. we located in killeavy south Armagh south of newry. the boiler is a firebird 44kw. before it was a 28kw but as 9 extra radiators where installed i resized the boiler. but as the 44kw has 1 1/2 bsp tapings i bushed it down to inch bsp. and upsized the pump. the heating vent goes into the roof space in 15mm copper which is now upsized. to 28mm from the floor of the attic to top of attic.

 

[tamz]

Do a wee drawing of how its piped

 

[Best]

Apologies, - I didn't realise you are a plumber. Yes, a drawing of pipes would be good. The vent & feed pipes for back bolier will need to stay open.