wiring query on a promax 24/2 he

[pipshady]

Currently installing a Promax 24/2 HE boiler (I am Gas Safe Registered but i dont usually do boiler changes) and i have a wiring query.

The old boiler (a prima 60f) had wiring as follow

L N E SWL to pump and L to PUMP, now i m assuming the L to the pump is the pump over-run

now my new promax has L N E SWL and 230v back programmer,

basically what i need to know is do i need to run new wires to the progammer (currently a ep2002) or can i swap over the pump live in the wiring centre to run to the programmer?

Its been a while since i ve done any wiring that was nt like for like so forgive me for being a little rusty!

 

[pipshady]

am i confusing myself, the SWL is from the controls is it not? so in theory i would just connect SWL to SWL, N and E, and L?

 

[Whitespirit66]

The Promax doesn't have a pump overrun. You have to make some changes to connections in the EP2002.

1) Remove old boiler wire connections from Ep2002's connector blocks. Then -

EP2002-----------------------------BOILER
D--------------to-------------------S/L
N--------------to---------------------N
E--------------to------------------EARTH


2) Pump connections need to be -

EP2002----------------------------PUMP
B------------- to------------------L
N------------- to------------------N
E------------- to----------------EARTH

Hope this makes sense.

 

[pipshady]

this promax does have a built in pump over run, i just wired the swl and left the 230v back to the programmer blank, boiler fires on ch, meet demand, shuts off burner, runs pump over run and shuts off fine, HOWEVER, the boiler wont fire for hw with external controls calling for heat! i know the programmer is faulty and i m changing that, however the hw valve opens (its an s plan) and the tank stat (potterton ptt2) shows its below temp but the boiler wont fire, my brain is fried after a busy weekend, what am i missing here!?

 

[pipshady]

sorry should have mentioned the promax has an intergral pump

 

[matt1e]

this promax does have a built in pump over run, i just wired the swl and left the 230v back to the programmer blank, boiler fires on ch, meet demand, shuts off burner, runs pump over run and shuts off fine, HOWEVER, the boiler wont fire for hw with external controls calling for heat! i know the programmer is faulty and i m changing that, however the hw valve opens (its an s plan) and the tank stat (potterton ptt2) shows its below temp but the boiler wont fire, my brain is fried after a busy weekend, what am i missing here!?

Do you have a multimeter? you need to check that the HW zone valve's microswitch is making or wired correctly

Matt

 

[picasso]

Are you sure its a promax ? as its coming up as a heat only boiler.

just found the promax 24/2 system HE plus , is this your boiler?

 

[pipshady]

yes i have multimeter, zone valve light is on and definatly opens as i felt the heat transfer past the valve from the ch, i ve got a feeling its the tank stat or programmer.

and yes it is a 24/2 he plus, (sealed system boiler)

 

[picasso]

It wont be the tank stat or programmer if the valve is opening, check both of the orange wires are connected properly.

 

[pipshady]

okey dokey, many thanks i ll check it out tomorrow, i removed the old pump wiring from the wiring centre today so i probably dislodged something!

 

[Whitespirit66]

this promax does have a built in pump over run, i just wired the swl and left the 230v back to the programmer blank, boiler fires on ch, meet demand, shuts off burner, runs pump over run and shuts off fine, HOWEVER, the boiler wont fire for hw with external controls calling for heat! i know the programmer is faulty and i m changing that, however the hw valve opens (its an s plan) and the tank stat (potterton ptt2) shows its below temp but the boiler wont fire, my brain is fried after a busy weekend, what am i missing here!?

Apologies. I thought we were talking heat-only.