Boiler or Boilermate - that is the question!

Ok I have an Ideal Classic FF340 boiler in the garage and a BM2000 upstairs in an airing cupboard. I have a plumber turning up later today - ex British Gas , reliable bloke by all accounts. But I like to understand my systems as I'm a bit of a computer buff.

Over the last few weeks I have noticed that the rads haven't been getting as hot as they can (used to be very hot to touch years ago). The room stat is set at 22 degrees but it never gets there. DHW was ok most times. So, I was planning on having the system serviced.

Two days ago the boiler, sensing I had plans, decided to play up. It comes on and after a short while (don't know how long as I can't be hanging about in a cold garage watching it) it stops firing. All pumps appear to be working - emergency switch operates it and rads warm up. The store temperature continues to rise. As I type it has climbed back to 64 degrees and is now on the way down - Could be just residual heat from the last burn (Oh I tell a lie it's gone up to 68 now). My computer room is opposite BM cupboard so I can watch it. LED1 and LED2 both on. Horizontal STORE bar only is on. The left hand boiler pump is running - removed silver screw to check.

The store temperature gets up to 70 degrees overnight (never seen the top setting) but the CE pump doesn't kick in so it's very cold. If I switch to the emergency CE and HW the CE pump starts and I get some heat from the rads (but the store temperature drops to about 45 degrees) . It can maintain around 18 degrees in the living room - bearable with thermal undies on.

About 4 years ago I replaced the PCB in the BM because I had a tropical temperature scenario.

Today I decided to check some voltages. At first the room stat SL and L had 240VAC on them - which you'd expect with room stat closed - so the boiler should have been running but wasn't (well, certainly not by the time I got downstairs to check it.) Elsewhere on the internet someone suggested powering off the BM for a while then switching back on. Now I'm not getting 240VAC on the room stat L (and consequently SL). Does anyone know if the L should be permanent? (I'm guessing it should be) There aren't any fuses that I can see so I'm wondering if the PCB has given up - although tests with link 5 in place seem to run ok.

It seems to me that the BM control PCB is at fault (£200 every 4 years? Ouch) but I could be wrong. I can get a replacemnt in a day or so.

Well, that's about it.If anyone can give an opinion before the plumber arrives at 5 today I'd be very grateful - I seem to be going in circles reading forum after forum.

I'm planning on putting a wireless Raspberry Pi and camera in the garage to monitor the boiler flame up here on my PC.

Best regards

Hi it might be worth checking the store temperature using SW2 to see what impact the boiler is having in raising it to the required level. The BM relies on the boiler maintaining the store temperature to work. This video gives some idea on the temperatures etc. If the pcb is suspected I can repair them for a lot less than a new one or provide a reconditioned replacement again for a lot less than new. See www.murraymartin.co,uk for more details. Cheers Murray

The store temperature gets to over 70 degrees at times - I have to switch to emergency periodically to get the house warm because the CE pump doesn't start. Plumber fitted a new thermistor to boiler and it ran for a while but things got back to 'abnormal' after an hour or so. I have already ordered a new PCB but I could be interested in having the existing one repaired as a future backup - let me know what you charge.
Having done some checks - theres no voltage on the room stat Live. The DHW pump doesn't come on when I run the hot water. The heating pump doesn't come on when the system is in Normal but runs fine in Emergency. Boiler pump does come on. The self diagnostics seem to run ok. The fuse on the PCB is ok.

Definitely get a new pcb off Murray if you’re needing one I got one off Murray at Xmas I fitted that and two new pumps and valves and the boilermate is working better than it has in years. Now my boiler fan is on its way out so that’s my next repair. But Murray offered me lost of advice and was an absolute gem when I had no heating at Xmas. Video on how to remove / replace and what the pcb would look like at it ran through the sequences. Don’t pay the extortionate prices get a reconciliation one from murray. You might even get my old board
Lol. Good luck Lenny

I changed the pcb 4 years ago when the house became a sauna. The system was 14 years old at the time. I'm disappointed that a new board has only lasted 4 years, hence I'm interested in a refurbished PCB for backup. Then I can rotate when each breaks.

It's a sad state of affairs that these boards go down so often. Maybe just unlucky.

On a plus side, I read that sensors often fail but mine, at 18 years old seem to be ok as far as I can tell.

The new board should arrive tomorrow.

Regards
Brian

Hi Brian - GT155/GD131 repairs are £45 including return postage. Thanks for the complimentary feedback Lenny glad I could help.

Did you get one off Murray hope you haven’t paid gledhill prices. Honestly Murray is your man you could have 6 off Murray for the price of the others my board had been on since 2002 but it had been wrong a long time but I didn’t know about Murray until Xmas time. As a single parent raising two kids as you can imagine the thought of hundreds ontop of the pumps and valves and at Xmas just struck the fear of god into me. But the pumps I had purchased a few years ago and pontificated about fitting. Then after loads of questions on here and research you tube and google I pulled up my big girl pants and did it. That and the fact it was bloody cold lol.

You’re welcome murray is of been lost and very cold and in minus figures in the bank if you hadn’t helped

Ok, left the thing running on emergency all day (on 2 hours, off 1 ) to keep the electric bills down whilst the replacement turns up - House is fairly warm, I don't need a jumper on. Store temp didn't get much above 50 so not providing much hot water. Rads warm not hot. DWH temp is nor brilliant - but then it wouldn;'t be with a low store temp.

Just now switched the BM back to normal mode to get the store temperature up - damn thing is working again. Perhaps it knows that I ordered a replacement?

Seriously, yesterday there was no signal voltage Live to the room stat. The heating pump didn't run except in emergency mode, same for DHW pump.

Just checked the room stat live and it now has 240vac on it and the CE pump is running. It is haunted I tell you!

Now, seriously, 4 years ago I changed the controller (it was like a sauna in here) I remember switching it off, waiting some time then switching back on (you know where I'm going with this) and it worked again - for a while. Then went tropical again so I changed it.

I suspect the same thing is going to happen this time but Icelandic instead of tropical.

So it seems there's a heat sensitive component that fails one way or another. (not a very good design if you ask me). If I had the circuit diagram I could probably track it down (Electronics and computing are my hobbies)

Question is, Murray, I'm willing to send you this naughty board to repair as a spare but will you be able to isolate the fault as it seems to be heat dependent? You might need to put your test rig in an oven for several hours to check it is fixed. On the plus side I won't need it back next day. I'll contact you via your website when I've swapped the board out tomorrow.

Incidentally, I ordered the replacement from keeptheheaton. I bought the previous replacement pcb from them. Price has hardly changed - £240 inc VAT and next day delivery. I don't know what Gledhill prices are like but my plumber said it would be cheaper for me to buy on the internet than go through him as he has to pay top wack.

Thank you all for your comments, much appreciated.

Hi don't worry it will work once I have had my sticky mits on it, guaranteed, if it doesn't then I will sort it, (it will work) (-:

As suspected the Live feed to the room stat has gone away again - this morning it measured 8vac - mostly, when faulty, it measures almost zero. When the system works it's 240vac. Thank god for the emergency switch!

Of course, without a feed the central heating pumps don't switch on because it looks like the room stat is a happy bunny. Why the hell the board is modulating the feed to the room stat I really don't understand (must be an active regulator component somewhere). Surely it should just be a switched feed to the pump? (rhetorical)

I just feel I could do better with £20 of electronics components (Arduino and main voltage relays). At least, with an Arduino it'd be a doddle to reprogram with a laptop and get some detailed status messages like "Do you know there's no feed to your room stat" or "it's taken an inordinate amount of time to heat the store - check your boiler!" , "Pump not drawing any current - probably stuffed" or even a rolling log file of what's happening and when - so you can see degradation taking place before it dies completely. Could even send text alerts. hee hee

Oh well, the new board arrives at a Matalan near me whilst I'm out on the golf course this morning/lunchtime so it'll be fitted and I'll send the faulty one off to Murray.

Hope this info helps others know where to look when their central heating doesn't come on but the store temp gets above 60.

Hi the mystery behind the strange voltages on the stat is due to the fact that the stat is really just providing a signal to/from the electronic chip on the pcb and when the logic goes doolally it affects the voltages.

Ok, Murray, that confirms to me that it's stuffed (as if I couldn't tell) and you'll know where the problem is. I'll contact you via your website when it's ready for posting to you.

(I bet they use chinese components LOL)

Regards
Brian

Brian could you contact keep the heat on tell them you’ve changed your mind re the pcb and have decided to replace the whole thing. Send it back for refund. Get a new one from Murray send your old board back for him to repair for a spare and you’re still £100 better off. I was just thinking outside the box. Have you had any power cuts recently that may have caused a power surge to the system to fry the components?

I appreciate the suggestion but the replacement arrived 30 minutes ago and I have fitted it. Ran diagnostics and fitted links in the correct places. I'm watching the store temp like a hawk right now. It isn't getting very high (hovering between 58 and 61). But it does now pump hot water around the rads for a short while (temp drop causes that to stop) and there is 240VAC on the room stat live, which the old board was forgetful at providing.

I think there's also a problem with the boiler temperature output in that it takes ages for the store temp to rise - but I have asked the plumber to give it a service soon anyway. As long as I can survive the night till then ...

The plumber brought a new thermistor for the boiler on Monday after I gave him some behavioural feedback. He wasn't going to fit it when I told him about the room stat live missing but I insisted he did - to eliminate a future problem (They are susceptible to packing up apparently).

I didn't know Murray had boards lined up for immediate shipment when I ordered the board from keeptheheaton. :-(

I will send the old one to Murray for repair and will deal with him in future - wish I'd known about him 4 years and a couple of days ago.

Thanks again Lenny

Well at least you’re a little further and you are more knowledgeable than I am re the boards. At least you’ve got a board and a back up once Murray’s worker his magic. I’m same at mo bearings are going on my boiler fan but got new bearings in and just working up to fitting them lol. Fingers xd we all gets decent working system before too long lol. Good luck

I tried that - the bearings are as common as muck and can be bought in a 'kit' from Ebay for £3, short written note on how to do it with two bearings. Mine have 626Z stamped on them - you can get 5 for £2.53 on Amazon and watch the video on YouTube. Fitting is not as easy as they make it look. But your fan may be different to mine.

When you release the top bearing (the easy one to do) the nuts under the motor, holding the top bearing in place, fall out - if you don't watch out for that they go on holiday somewhere obscure.

The hard part is releasing the lower fan (grub screw) so you can withdraw the motor and get at the bottom bearing. I could not budge mine. Having sent the nuts on holiday in the garage somewhere I gave up as it's too cold to prat about. I was hoping to refurb it and hang on to it as a spare since they seem to go every 4 or 5 years - design fault sitting on top of a heat chamber where it gets, well, real hot.

Bought a wrong 'un replacement fan for my Ideal Classic FF340 off Amazon. Watch out for electric combi boilers - the picture on Amazon is the correct fan but isn't what they delivered and they say that's all they supply for my Classic. I'm going through the motions of a refund but they are so slow to respond to email - told them I want the return postage paid by them as the description was incorrect. Push came to shove and I ended up buying a fan locally for £140 :-( It's been an expensive February.

I'm glad I didn't try to repair the old fan first - I would have been without a boiler.

Your motor may be different to mine,

Good luck.

I found a video on you tube and msgd the poster as he had indicated that he sold the bearings for £3 delivered I think looked on eBay for the fans and the bearings I found a suplloeryand thought if they’re wrong for the £3 I could stand the loss. Luckily I had emailed the you tube poster and the seller and it was the same guy. So I have the bearings and will probably attempt next week when kids are back at school less chance of interruptions. If I get stuck I’m quite fortunate that my dad bless him (81 this year) is a whizz at stuff like this but I like to have a go myself and not disturb him. So I will have an attempt but dad’s my last line of defense. My kids have grown up saying of Grandad can’t fix it, it can’t be fixed lol. I did suspect it was a bigger job than the video eludes to. Thanks for the info tho I will definitely use the info. We’ve a local acrewfix opening tmrw and there’s 10% off for purchases so I’m contemplating some cleaner and inhibitor and a magnetic device to reduce sludge and make they system more efficient. Wished I’d known I was capable of all this and done it years ago but I do like to research and try to make sure I don’t stuff it up and learn an expensive lesson. We don’t like those lessons

Too good to last. 5 hours of good behaviour with new ACB.

Room stat Live from new board has gone walk about like before. Store is now at 71 degrees. Room stat is calling for heat. No LED lights on the board just numeric display lit. No pumps running - rads cooling down - won't be long before I get back into my thermal underwear.

The cupboard door is open so I can watch the store temperature from my desk so it hasn't gotten too hot in there.

This is killing me - in so many ways. Hope it isn't a pump taking out the board - they all appear to run ok - when they do.

Has anyone got any ideas?

How old are the pumps? Have you taken the bleed screw out of the pump and seen the colour of the water and just twisted a screwdriver to make sure the pump is free to move and not ceased. With all power turned off obviously. Sorry that’s about the limit of my knowledge base except how to replace. I replaced mine with grundfos ups2’s the only one I haven’t replaced is the hot water one that’s direct from gledhill due to the speed it’s set at. Hope you find a solution

All grundfus UPS. They do spin, I've had the caps off, clear water, and I can see they turn.

I appreciate that if the startup current for the pumps is higher than normal it may cause the firware to barf. But the missing roomstat feed is the most perplexing thing - no feed means no call for pumps to run.

Lo and behold the Live voltage is back.

Have passed info to Murray via email.

Thanks for suggestions - all are welcome

Murray is a legend. Via several emails he talked me through the fault finding (I'm handy with a DVM)

It appears to have been the timer.

"What?" Yes, timer! I would never have guessed that, and actually thought it odd to be asked to check the voltage coming via the switched live.

When off it disconnects the live feed to the room stat (bless) which means heating isn't called for. I think the original digital clock was faulty - I changed it for an electro-mechanical clock (on Tuesday) which is easier to read and more obviously permanently on (I have a Drayton programmable room stat so don't need the timer as such.).

I'm sure I swapped the wires over as fitted to the digital but one wire was wrong - so when I thought the system should be on it was off hence it wouldn't do central heating when I expected it to and hence the apparently missing room stat live feed. And me ripping hair out.

So simple.

It's been working a couple of hours now with store temps ramping up and down as the heating kicks in and out.

Before you ask, yes I'll be sending him the old pcb to be checked over so I can keep it as a spare.

Thank you Murray.

He’s a total legend and a true Gent. Pleased you’ve got sorted and will have back up for the future fingers xd you don’t need it and probably Sod’s law if you have a spare there just in case it might never fault again. Here’s a to a toasty night

Ok, things have been quite comfortable since Murray helped me pin the fault down to the electronic clock on the BM intermittently switching off the call for heat - bless. (series wired with room stat). And he's refurbed my control board (now kept as a spare).

But I still think I have a boiler output temperature issue.

Being a nerd I strapped some temperature sensors to the flow and return on the boiler and took readings at 1 minute intervals for 24 hours using a raspberry Pi Zero. Interesting graph (attached if you want to look at it - I showed it to Murray). The max temperature recorded was mid sixties BUT there could be some discrepancy because the store says it got up to 73 during that period. So, maybe water in the pipes is 8 degrees higher than the copper pipes or the thermometer contact with the pipe wasn't too good - the sensors I used are digital, temperature compensated and supposedly quite accurate (0.5 deg) and very affordable.

Anyway, today, out of curiosity, I looked at the BM store demand and satified temperatures and they are 61 and 68 respectively, instead of 74/77.

I believe the BM adjusts it's expectations based on boiler performance. Does this confirm the boiler output is low?

The boiler manual says that on max setting it should achieve 82 degrees but since the boiler is in the garage and the BM upstairs there's something like a 4m run (if the pipes go where I think they go).

Would resetting the BM do any good?

Since starting typing the demand temperature has risen to 65, satisfied is still 68 and the store to 72 - it's a weird world to be sure.

Any thoughts?

Regards
Brian

Hmm, didn't attach - went to try again and I get a 'max size per file 0mb'. Maybe my profile denies it - but I got no warning. If you want to see it maybe a priovate message would work. Meanwhile I'll check my profile.