Vaillant 418 wiring into Y plan

[Longhouse]

I'm about to have my old boiler replaced (Glowworm Spacesaver 60k) with a Vaillant 418. I'm staying with an open vent system and the existing controls (because I prefer simplicity, hot water storage and the controls are relatively new). Can anyone clarify the wiring requirements?

The system currently uses a Siemens RWB9 controller, Sunvic TLX7501 room stat, cylinder stat, Sunvic mid position valve and is wired according to the Sunvic Unishare diagram here: http://www.sunvic.co.uk/uniselect.pdf

Am I correct in assuming that I need to modify as follows:
1. Permanent live feed from switched side of isolator upside of the controller
2. Single wire switched live feed to boiler term 4 (with link removed 3 - 4) from term 10 of the JB on the Sunvic Y plan drawing
3. Remove pump switched live feed from term 9 of the JB in the Sunvic drawing and feed pump only from the pump connection terms on the new boiler

New wiring proposals can be seen here (hopefully!)
//media.diynot.com/130000_129671_16438_21058043_thumb.jpg

 

[Longhouse]

Can anyone help to clarify my understanding of the way to connect the new boiler? Need to be able to check that I have the right number of cables / cores in the right areas so that the installation by the installer (this weekend) goes smoothly.

Thanks

Longhouse

 

[kevplumb]

might be able to if the wiring you propose was not on a postage stamp

 

[Hugh Jaleak]

Can you enlarge the proposed wiring diagram please! Unable to make anything out in its present form!

Point to note, I dont know how old the Unishare valve is, but they are known to be troublesome. See this guys page! http://www.seered.co.uk/sunvic.htm

Ive just replaced mine after 3 years service for the Honeywell version. It had a tendancy to stick open to both ports, so the CH wouldnt shut off until the HW was satisfied, and this obviously took longer as some of the flow from the boiler was going round the CH circuit..... If the system is drained whilst new boiler is fitted you may wish to swap it at the same time.

 

[Longhouse]

Hi gents, thanks for the quick responses and advice. I'm new to the forum and hadn't realised the link showed up so small! I've tried editing the picture file, increased the file size and uploaded again but it still refuses to view any larger when I preview and click on the link?

I've followed the instructions on uploading and can't see where I'm going wrong? When I view in my album it comes out in large scale and clear! Any ideas on how I can improve the size for general viewing?

Point on the valve noted, but that, the pump, H/W storage tank, room stat, cylinder stat, thermostatic rad valves and auto by-pass have all been replaced/upgraded within the last 12 - 18 months (after around 20+ years of service) due to either failure (tank & pump on separate occasions) or the general need to improve the system performance. Boiler now being replaced because I need to move it out of the kitchen into the attached garage to create space for the kitchen upgrade (swmbo).

edit for link to imageshack (hopefully this works because it does when I preview!)

http://img692.imageshack.us/img692/6186/yplanwiringdiagramvaill.jpg

 

[Longhouse]

Gents

please see the new link for drawing:

http://img692.imageshack.us/img692/6186/yplanwiringdiagramvaill.jpg

 

[picasso]

your new plan will work fine, so just to be clear the dotted line (permanent live ) will have to be fitted.

 

[D_Hailsham]

The boiler terminal marked P/L is a permanent live and should be fed from terminal 1 of the junction box as per your dotted line.

There is no need to link 8-9-10-boiler S/L; just connect boiler S/L to terminal 8.

If the pump is close to the boiler, it can be wired in directly to the boiler pump terminals as in your diagram.

If the pump is near the junction box. connect the pump N and E terminals to 2 and 3 in the junction box. Connect the pump live to terminal 9 or 10 and run a wire from here to the boiler pump L terminal (the N and E terminals are not used). This will require a 4-core plus earth cable from junction box to boiler - L, N, E, S/L, Pump Live.

 

[Longhouse]

Thanks for the confirmation - I was a little confused by the wording in the boiler manual I'd downloaded (why can't they just give a proper typical loop drawing to follow!). The only other mod that I'll make is to provide local isolation of the P/L and S/L connections adjacent to the boiler as the existing main isoltion is adjacent to the programmer which isn't visible from the boiler - different room (and label them as requiring isoaltion at the programmer for work in the incoming side of the boiler local isolator). And when it's done, I'll put the "as built" drawings on file in the house folder.

Thanks

Longhouse