Old system playing up

[Dan hart]

Hi all

I'm new here so thanks in advance, I have an old Netaheat boiler set up (gravity fed) which failed to fire up for central heating last week, I have set the three way diverted valve to manual and have been using the "call for hot water" to heat the radiators (once its been on for half hour and nice and hot I do get nice hot water pouring into the expansion tank) so want to get this resolved asap, tonight I bought a full Honeywell v4073 and swapped out the head, however, this hasn't remedied the issue, the spindle still seems loose enough (can turn by hand) my thermostat (old wired type - non digital) is set to full and clicks in and out & the controller (old lifestyle Lp722) led come on when I advance for central heating with nothing happening elsewhere.

I have removed the new valve head from the brass valve itself to see what happens when I switch from call for hot water/call for both/call for central heating only and it does nothing.

It is most likely that
A. The new valve head is duff
B. The controller is duff
C. The thermostat is knackered
D. Other

It has all previously worked well so I doubt a wiring fault, I'm skint and a well experience diy'er & would never mess with gas FYI, just after a few pointers to narrow the fault until I hav to go cap in hand to relatives for plumber money!

Thanks

Dan

 

[Last Plumber]

Thank you, what about cleaning or is a flush through with fresh water a couple of times normally enough?

I would put F3 Cleaner in, leave it a few weeks, Get it hot and empty it. Then refill, dose with F1 and Balance !

I would do this after the pumping over the vent pipe has been dealt with though otherwise, you'll be wasting your efforts.

 

[ShaunCorbs]

Ah!
Another amazing invention.
They would all outlast any modern effort!

Yep had one had to get rid flue was smelling a bit

Even had the upgraded cast hex, it's in the local tech collage now

 

[Last Plumber]

Yep had one had to get rid flue was smelling a bit

Even had the upgraded cast hex, it's in the local tech collage now

See....it lives on...even wounded!
Warriors !!

 

[Ric2013]

From the instruction manual, the heat exchanger looks to be cast iron. Certainly the Potterton Netaheat Profile, later renamed simply 'Profile' has a cast-iron heat exchanger.

Re water pouring into your cistern, you mean the hot water comes out of the vent pipe over the top of your feed and expansion system and runs into the cistern? A run or a dribble? Does this continue to dribble when the system is good and hot and has been running for some time?