ferguson_tom Posted February 28, 2012 Report Share Posted February 28, 2012 Hi everyone Need some help my gas combi boiler is beginning to cost me a lot of money. Over summer it completely packed up so we just made do as didnt need the heating. Before xmas we got the pcb replaced and it serviced which got the central heating working but no hot water. Just had the diverter valve and hot water thermistor replaced but still no hot water. When you turn the hot water tap on the boiler does not even fire, or if the boiler is on and running the central heating the diverter valve does not switch it over. Is there a micro switch or flow sensor in the system that tells the boiler the hot water is required as this is where i reckon the fault lies? Its an Ideal Isar 24 combi. I dont want to get the engineer round again to replace another part that dont fix the problem. Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
daz2202 Posted February 28, 2012 Report Share Posted February 28, 2012 Sounds horrible but the isar is well known to be one of the worst combis out there, maybe worth getting another cheap combi, glow worm do a beta on for £525 with flue and clock! Quote Link to comment Share on other sites More sharing options...
Doc Holliday Posted February 28, 2012 Report Share Posted February 28, 2012 If you've had the diverter valve, the pcb and the hot water thermister replaced then there's not a lot left to be honest. I would say it would be under warranty of some kind as you've had all those parts replaced and it still not working. There is a microswitch that gets activated by the diverter valve when you open the hot tap but if the boiler guy you had was half way decent he should have checked that before replacing any parts. Get him back to sort it, if he's a professional engineer he won't have a problem with that. Quote Link to comment Share on other sites More sharing options...
scobydog Posted February 28, 2012 Report Share Posted February 28, 2012 Could be the thermo coupling, ask the engineer if he checked it, don!t know about yours but usually cost @ £20 to buy and @£50 to fit, takes about an hour. Good luck with it anyway. Quote Link to comment Share on other sites More sharing options...
Canis Posted February 28, 2012 Report Share Posted February 28, 2012 It sounds like its the differential pressure switch - either the diaphram has gone or the microswitch is gone being the most usual ! fault finding will be in the O&M manual that should have been left with the boiler and should be laid out such that a novice could follow it. i'm not going to advise you to do that yourself though as I would be be inciting you to an ilegal act on a public forum! Quote Link to comment Share on other sites More sharing options...
ferguson_tom Posted February 28, 2012 Author Report Share Posted February 28, 2012 Cheers canis that is what i expected something like a microswitch, i have already looked at the fault finding thing that comes with the boiler but like the boiler it is a ***, i would never do a thing like try and fix a boiler myself Quote Link to comment Share on other sites More sharing options...
vampire Posted February 28, 2012 Report Share Posted February 28, 2012 Long shot,but have you tried moving the wire from the micro switch,that was a problem on my ideal 24 which was foung out after spending £500 wish i had just fitted a new boiler The engineer just replaced parts till it worked cause he didnt have a clue and wanted us to have a new one Quote Link to comment Share on other sites More sharing options...
Asa Bear Posted February 28, 2012 Report Share Posted February 28, 2012 It sounds like its the differential pressure switch - either the diaphram has gone or the microswitch is gone being the most usual ! Quote Link to comment Share on other sites More sharing options...
-Mongrel- Posted February 28, 2012 Report Share Posted February 28, 2012 It sounds like its the differential pressure switch - either the diaphram has gone or the microswitch is gone being the most usual ! If the diverter valve has been changed then the diff pressure switch diaphragm is usually part of that so you need to confirm that was the case. If so then the engineer should have verified that the microswitch is being actuated, basically the diaphragm operates a plunger on a pin which moves to depress the microswitch. If this is occurring then it's a case of then checking that the power is being switched through this microswitch, if that is working it is coming back to the PCB, but that is new so.... ...coming back to the plunger and pin, IF that isn't moving, you need to have serious words with your engineer, I now of several cases recently where people have been charged for a diverter valve where in reality it's been stripped and had a new diaphragm fitted. Quote Link to comment Share on other sites More sharing options...
Martin2 Posted February 28, 2012 Report Share Posted February 28, 2012 skip it get a vaillant or a glow worm. Quote Link to comment Share on other sites More sharing options...
daz2202 Posted February 28, 2012 Report Share Posted February 28, 2012 Could be the thermo coupling, ask the engineer if he checked it, don!t know about yours but usually cost @ £20 to buy and @£50 to fit, takes about an hour. Good luck with it anyway. No thermocoupling in this boiler it's electronic ignition Daz skip it get a vaillant or a glow worm. Best advice given all day, evening Martin Daz Quote Link to comment Share on other sites More sharing options...
-Mongrel- Posted February 28, 2012 Report Share Posted February 28, 2012 (edited) skip it get a vaillant or a glow worm. LOL, yeah, spend £1400+ to get another boiler fitted when you've already paid someone to fix it. If it's a reputable engineer they'll come back and sort it, it may need further parts, but certainly not 1400 quids worth. To be honest, it can only be one of a small number of things and a competent engineer will sort it pretty easily. Oh yeah, and if it comes to it, DON'T get a Gloworm, they're no better than what you have, Vaillant and Worcester Bosch consistently fight it out in the Which? magazine tests for good reason, they are a cut above. Edited February 28, 2012 by -Mongrel- Quote Link to comment Share on other sites More sharing options...
daz2202 Posted February 28, 2012 Report Share Posted February 28, 2012 LOL, yeah, spend £1400+ to get another boiler fitted when you've already paid someone to fix it. If it's a reputable engineer they'll come back and sort it, it may need further parts, but certainly not 1400 quids worth. To be honest, it can only be one of a small number of things and a competent engineer will sort it pretty easily. Oh yeah, and if it comes to it, DON'T get a Gloworm, they're no better than what you have, Vaillant and Worcester Bosch consistently fight it out in the Which? magazine tests for good reason, they are a cut above. Beg to differ, I sell in excess of 400 boilers per annum, glow worm currently seem to be the best for price reliability and after service. I would like to add also that if you like valiant so much then why not glow worm. They are the same company and made in the same factory!!! Worcester I agree are also very good but boy do you pay a premium for there badge. The isar that was at first mentioned is unfortunately one of the worst, Ideal boilers have since bucked there ideas up and there boilers have improved. Seriously I would consider changing it as long term I would be surprised if you ever go a whole year without a breakdown. Daz Quote Link to comment Share on other sites More sharing options...
scobydog Posted February 28, 2012 Report Share Posted February 28, 2012 No thermocoupling in this boiler it's electronic ignition Daz Best advice given all day, evening Martin Daz Hi Daz ,mine kept doing same so just thought it was same problem, i've got worcester bosch now great bit of kit. Quote Link to comment Share on other sites More sharing options...
PWD Posted February 28, 2012 Report Share Posted February 28, 2012 (edited) I had this on my boiler...on mine there was a magnetic sensors (I think ) that detected water movement...swap these quite regular about once every 18 months and I have no issues..cheap and easy to do..about £18 and an hour..most is striping the cabinet away...that said the last lot have been OK for the last 3 years ..probably pack in now Edited February 28, 2012 by PWD Quote Link to comment Share on other sites More sharing options...
Martin2 Posted February 28, 2012 Report Share Posted February 28, 2012 Good evening how's the bird watching? . Quote Link to comment Share on other sites More sharing options...
-Mongrel- Posted February 28, 2012 Report Share Posted February 28, 2012 I had this on my boiler...on mine there was a magnetic sensors (I think ) that detected water movement...swap these quite regular about once every 18 months and I have no issues..cheap and easy to do..about £18 and an hour..most is striping the cabinet away...that said the last lot have been OK for the last 3 years ..probably pack in now You have a flow switch mate, the Isar uses a different system. Quote Link to comment Share on other sites More sharing options...
daz2202 Posted February 28, 2012 Report Share Posted February 28, 2012 Good evening how's the bird watching? . 20th feb came and went, as again I was just armed bird watching again!!! Quote Link to comment Share on other sites More sharing options...
ferguson_tom Posted February 28, 2012 Author Report Share Posted February 28, 2012 (edited) thanks for all the responses, it might be something even simpler. I called up ideal and there is a chance the pcb pins are only configured for heating only and not hot water aswell. what a stupid idea anyway they said couldnt actually tell me the correct configuration as not a registerred engineer. so to deal with a pcb board i need to be gas safe registerred..... Edited February 28, 2012 by ferguson_tom Quote Link to comment Share on other sites More sharing options...
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