DIYnot
Local | Network
   DIYnot > Forums
Local | Network
DIYnot Network Local DIYnot Network Local  
  Forum IndexForum Index     RulesRules    HelpHelp     Join FREERegister Free     About CookiesCookies     SearchSearch     LoginLogin 

Ferroli Optima Honeywell VMF7 PCB Relay Fault


 
Post new topic   Reply to topic    DIYnot.com Forum Index > Plumbing and Central Heating
Search this topic :: View previous topic :: View next topic  
Author Message
Helli

from United Kingdom

Joined: 27 Mar 2010
Posts: 10
Location: United Kingdom
Thanked: 1 time

PostPosted: Sat Mar 27, 2010 7:01 pm Reply with quote

My Ferroli Optima Boiler struggles to ignite due to a buzzing/chattering Relay. Apparently this is a fairly common fault and a new PCB costs about 180.

The chattering Relay is the one to the far right of the PCB and often looks burnt due to the sparks caused as it chatters. After much searching and testing I've managed to cure this fault for about 6.

The chattering relay is actually caused by a breakdown in the small blue capacitor located close to it. This can be replaced for about 20p with a 10uF 100v (or bigger) electrolytic Cap. Don't worry if the replacement is physically bigger, just bend the legs. This may cure the fault; if not and the relay's knackered, replace the relay with a 48vDC 8A double pole one. The SCHRACK original seems difficult to locate in the UK but I got a similar spec one off ebay for 5 and it works great.

Thanks to Mr Bardwell on Abbeydale Rd Sheffield & Hartley Electrical Repairs on London Rd Sheffield for diagnosing the capacitor as the cause of the problem. Saved me 's! :D
Back to top
The following user says thank you to Helli for this useful post:
JohnBD (5 Feb 2011)
 Alert Moderators

If you do not want to see this advert, click here to login or if you are new click here to join free.
JohnBD

from United Kingdom

Joined: 05 Feb 2011
Posts: 2
Location: Lancashire,
United Kingdom

PostPosted: Sat Feb 05, 2011 12:33 am Reply with quote

Hi,
I appreciate this is a relatively old post, but I have just encountered the same problem on my boiler and wondered if you could give me a bit more detail on the location of the relay and how to remove the PCB etc. It looks quite straight forward but worried in case there are any hidden screws etc. Many thanks
Back to top
 Alert Moderators
Helli

from United Kingdom

Joined: 27 Mar 2010
Posts: 10
Location: United Kingdom
Thanked: 1 time

PostPosted: Sat Feb 05, 2011 10:40 am Reply with quote

Hi John,
I'm no heating engineer but it's a pretty straight forward repair. Assuming you've got to the PCB by unscrewing the front, switch off the power and take some good photos of which wires go to which connections - label them if need be. Pull off all the wires, unscrew the PCB and take it out. Unsolder the capacitor next to the chattering relay and replace with the one I've detailed. You'll get one from any electronics place, Maplins etc. Note it has to be an 'electrolytic' type (I'm told). If the relay doesn't look to bad i.e. Not all black and case melted, I'd try it with just then replaced capacitor as it's that that causes the chattering in the first place not a faulty relay. If it doesn't work you'll have to take it out and replace the relay which I found on eBay. I've b*****r about with this fault for ages and it's a common fault with these boards, so i was dead chuffed when Messrs, Bardwell and Hartley got to the bottom of it and saved me about 170. Let us know how you get on.
Back to top
 Alert Moderators
Agile

from United Kingdom

Joined: 26 Jun 2004
Posts: 53363
Location: London,
United Kingdom
Thanked: 3383 times

PostPosted: Sat Feb 05, 2011 11:31 am Reply with quote

You dont say what that firm charged you! I dont imagine they did it free!

Whilst I dont encourage DIY repairs on PCBs that is an option for someone with a good understanding of electronics.

But its not quite as simple as the OP says!

Electrolytic capacitors are polarised. That means the have a + and a - connection and have to be fitted the correct way round.

If thats not done then it could damage another part of the PCB or even create a dangerous condition as the PCB controls the gas valve and thus has a safety aspect.

Replacing a relay which operates the gas valve with another make would create a modification to the PCB which has not approved by the manufacturers and could have safety implications.

Schrack and Finder relays are better quality and probably chosen because they are far less likely to jam on and create a dangerous condition than cheap chinese relays you might find on Ebay.

Tony
Back to top
 Alert Moderators
Helli

from United Kingdom

Joined: 27 Mar 2010
Posts: 10
Location: United Kingdom
Thanked: 1 time

PostPosted: Sat Feb 05, 2011 11:47 am Reply with quote

Quite right last poster, the capacitor does have a + & - leg which I was just logging on to re-post this info. So just check which way round before you desolder the original. Alternatively, you could get a heating engineer out to put you a complete new PCB in. I just posted the info so people know that a 20p component is the cause of the fault that I suspect often results in an expensive replacement. Entirely up to you which route you take. All the best with it.
Back to top
 Alert Moderators
JohnBD

from United Kingdom

Joined: 05 Feb 2011
Posts: 2
Location: Lancashire,
United Kingdom

PostPosted: Sat Feb 05, 2011 3:48 pm Reply with quote

sorry, very new to the forum, and thanks to all for your help and advice. I should have said that I am en electronics engineer, although I haven't done this kind of stuff for many years. I just wanted to get as much info as possible from someone who had already done this job, and double check the location of the troublesome relay and capacitor on the PCB, If you could point me in the direction of the relay seller on ebay that would be very useful. I have found near but not exact equivelents on ebay and at Farnell and CPC.
Back to top
 Alert Moderators
Helli

from United Kingdom

Joined: 27 Mar 2010
Posts: 10
Location: United Kingdom
Thanked: 1 time

PostPosted: Sat Feb 05, 2011 4:18 pm Reply with quote

John, sorry I can't trace the eBay seller as it was some time ago but item 130364321191 looks like the one from my memory. Obviously you'll need to check the spec against the one one the board, DPCO etc but I think that's the one. As I said before though, unless yours has been chattering away for a while it might be fine when you fit the new capacitor. From what I remember Mr Hartley saying, the cap holds the voltage for a split second whilst the relay kicks in and then holds itself on. When the cap is shot, the relay can't do this and starts chattering. It seemed to make sense at the time but I'm sure will make more sense to you being an electrical engineer! I'd be interested to know how you get on. All the best.
Back to top
 Alert Moderators
MickH71

from United Kingdom

Joined: 18 Apr 2012
Posts: 4
Location: United Kingdom

PostPosted: Wed Apr 18, 2012 6:12 pm Reply with quote

Dear Helli My son is an excellent Electrician and I am an old -very old Commercial Heating Engineer. I hate combis for the fact that they always go faulty -usually at the wrong time but this Ferolli 700 Optima was probably the very best of all combis ever made for it's reliability. My son's combi has the same fault you mention and he replaced the two relays that appeared burnt (one was chattering) and not 'pulling in' as you mention. The board was put back in still same symptoms. He replaced three capacitors to no avail(the board is marked pos +neg so the observant won't make a mistake. Please may I ask if the folks in Sheffield you know of will repair this board.
Incidentally there was a 'working' second hand one available on eb so this has been a good temporary measure. This second hand board works. But it would be very interesting to know if a line drawing is available for this PCB ???? P.S. 16 years old & still good -can't be bad ! !
Back to top
 Alert Moderators
Helli

from United Kingdom

Joined: 27 Mar 2010
Posts: 10
Location: United Kingdom
Thanked: 1 time

PostPosted: Fri Apr 20, 2012 10:33 am Reply with quote

Hi, the guy who repaired mine in Sheffield is Pete Hartley http://www.hartleyelectricmusic.co.uk/repairs.html He's a real wizard with electronics, very helpful and won't 'lift your leg' with the cost. Cheers.
Back to top
 Alert Moderators
Search this topic :: View previous topic :: View next topic  
Post new topic   Reply to topic    DIYnot.com Forum Index > Plumbing and Central Heating All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Similar Topics   Replies   Views   Posted 
ferroli vmf7 ???? poss HELP ME the wife + kids R cold 6 340 Sun May 10, 2009 9:25 am
Ferroli 901 fan relay not working? 8 480 Sun Dec 28, 2008 6:51 pm
Connecting a Honeywell BDR91 Relay Box to a Baxi 105 HE 3 80 Sun Feb 23, 2014 11:48 pm
Honeywell HC60NG wireless relay unit replacement - help 7 2920 Sun Oct 14, 2007 6:52 pm
Honeywell CM67 relay switching noise 3 840 Sun Jan 21, 2007 11:25 pm


 
DIYnot
Find an Expert | Find a Supplier | Search DIYnot.com
Network | Advertising | Newsletter
DIY | DIY How To | @home | DIY Wiki | DIY Forum
By using this site you agree to our Terms of Service / Disclaimer.
Please read our Privacy Policy. Copyright © 2000-2014 DIYnot Limited.