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By avtur3
FLYER Club Member  FLYER Club Member
#1884523
So ... after 37 years of marriage and home ownership we have suffered our first central heating failure.

We're in house number 4, the first two were brand new from builders, the third was a much older house, and the boiler was about 30 years old when we moved in but gave virtually no problems in the 20+ years we were there. Is was old tech and not very efficient, but it worked.

In there current house, built in the 50's the boiler is about 12-13 years old. It is not an up to date condensing boiler but it does have some electronics in the control system. It appears the electronics have given up.
I called someone out, he thought there were some questionable joints on the PCB so had a go at re soldering them. That didn't wok so a new PCB was prescribed as being the answer to the problem.

After 72 hours without the boiler the new PCB should arrive and be fitted in the morning. I really don't like that I have no knowledge/understanding of the boiler systems and am totally reliant on the integrity/expertise of the heating engineer. He did come a result of a personal recommendation which I'm trying to tell myself is a good enough reason to trust what we are being told.

If all goes well in the morning and the new PCB is fitted and fixes the problem we'll be about £400 out of pocket. Given that this is the first boiler cost we have incurred in 37 years I am trying to tell myself that we've not done too badly ...
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By T6Harvard
FLYER Club Member  FLYER Club Member
#1884529
Indeed, you have done well over the 37 years :D

What were the symptoms prior to failure?

We had a pressure sensor go, total cost for part and fitting £70. Hot water was fine, but heating refused to do anything more than fire up for a few seconds then switch off.
By avtur3
FLYER Club Member  FLYER Club Member
#1884531
T6Harvard wrote:Indeed, you have done well over the 37 years :D

What were the symptoms prior to failure?

We had a pressure sensor go, total cost for part and fitting £70. Hot water was fine, but heating refused to do anything more than fire up for a few seconds then switch off.



We have a bog standard set up, vented heating and hot water with hot water cylinder. Boiler simply not responding to demand from cylinder stat or room stat. The boiler is a Baxi Solo, well known for PCB and fan problems.
By Bill McCarthy
#1884537
Do you have an “S” or “Y” plan system - two separate valves ( one for hot water, another for CH ) or a single 3 port valve to direct pump output to HW cylinder and / or CH. These have micro switches in the drive head to “tell” the programmer what position it’s in. They can stick with crud in the system and can’t cycle to open/shut position.
By avtur3
FLYER Club Member  FLYER Club Member
#1884563
Boxkite wrote:The time-line doesn't make sense in the OP. Is the faulty boiler only 12-13 years old?


Yes, boiler is only 12-13 years old, the boiler is not original to the house, perhaps I didn't need to state the age of the house :thumright:
By riverrock
FLYER Club Member  FLYER Club Member
#1884597
You've done well...
Our previous boiler had a new thing wrong with it a couple of times a year - British Gas were still happy to keep replacing bits on their servicing plan, so we let them keep doing it. We stopped organising an annual service because they were out so often.
New boiler had its PCB replaced by manufacturer under warranty after 4 months, after it kept complaining about things (has been fine since).

Independents can be good or bad. We had our church manse boiler fail last Christmas when British gas were on strike. Independent came and wanted to replace half the boiler. British Gas weren't happy so convinced one or their own engineers to look and it was just a blocked discharge pipe.
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By Pete L
FLYER Club Member  FLYER Club Member
#1884598
We nearly kept our old boiler - the PCBs weren't complicated and you still get some variant of them on Ebay.

But in the end succumbed to a new one. That also had a PCB failure after a few months, and a wonderful bug where it would runaway - presumably to make BG some more cash while we roasted.
By Big Dex
#1884602
Speaking as a qualified boiler chap (and I think possibly local to you @avtur3 in South Manchester, and happy to look FOC, definitely not touting for business), a PCB diagnosis is normally "engineer can't find an obvious fault". I presume that the switched-live to the boiler is getting the appropriate 240v signal when there is a demand? If not, the fault likely lies with a zone valve, time clock or thermostat.

If it is getting a demand signal, the order firing sequence is:
Fan switch detects no pressure
Fan runs
Fan switch detects pressure
Igniter sparks
Gas valve opens to low burn
Vitiation sensor detects flame
Gas valve opens to full burn

Most of these actions are visible or audible; be it the quiet click of a the fan switch or through the little sight glass in the combustion chamber.

If any of these actions occur, it is likely that the PCB is ok. If none of them occur, a thorough check of the wiring harness is in order. If all here is well; PCB is a probability (but check the little fuse on the PCB first!).

That being said, a Baxi Solo wasn't much good when it was new, and I would question investing £400 in a 12 year old one! It is very near the end of life, and that's half the cost of a replacement unit.
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By Bill McCarthy
#1884606
Good CH engineers are very thin on the ground - I called one in to check the exhaust gas temp and smoke content, because I didn’t own a detector probe (for oil fired boiler) - cleaning the heat exchanger baffles, doing a fuel nozzle change and oil pump pressure check is very simple . I was out at the time and Mrs McC pointed to the boiler. When he left he had changed the bliddy system circulating pump and knackered the timer/programmer - he shouldn’t have touched either but charged a mint for it. Never again - I now borrow a detector probe and do everything myself.
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By rikur_
FLYER Club Member  FLYER Club Member
#1884607
Big Dex wrote:Speaking as a qualified boiler chap .....

Out of interest - what should one look for when choosing a 'boiler chap'?
There's clearly to obligatory Gas Safe / Oftec bit.
But my perception is that installations are increasingly more complex and diverse than a decade ago. There's more electronics, sensors and fail-safes in the systems themselves. Then you add in zoning, Nest, Hive, Smart TRVs, etc etc, and it's becoming a small electronics project.
We had a great chap doing our oil boiler service for years (a basic Potterton Statesman). Best described as an old school plumber with 20+ years experience of what was likely to be wrong. He was a technician with training and life experience, (and all the relevant spares in the back of the van), but not really an engineer that could work out something he hadn't encountered before. When we got our new boiler with it's bells and whistles, we swapped to using their accredited engineers. They're younger, less experienced, but well trained in that product range, and can readily phone the manufacturer for guidance.
By Big Dex
#1884618
Hard to say; I guess for me the main point would be that they're a time-served and experienced boiler person, rather than a plumber doing bathroom fits amongst heating jobs. Knowledge of combustion performance analysis (gas analysers) is essential for all modern boilers; with the advent of zero-governors as now used on most boilers they are an essential tool to set up and maintain them. The manufacturers own repair team will always be experienced on a narrow range of products (no bad thing in my view) and should carry the spares on board for the majority of faults, and the British Gas team are by and large pretty good too, albeit at a price. The ones to avoid are the chaps who fix boilers by replacing random parts in a process of elimination, and always those who charge for their time driving around to collect parts. There should be a max of 2 visits: 1 to diagnose, and one to repair. All parts are available next day.

I'm no longer heavily involved in boiler repairs, having formed a construction company around 6 years ago, but I still keep my qualifications current and maintain the systems in my own personal and rental properties, plus the odd FOC job for clients, family and friends.

Best advice I can give (based on my personal opinion); stay away from Heatline, Biasi, Vokera, Main, Keston and Potterton boilers. Vaillant or Veissman are my personal preferences, and Alphas in rental properties (7 year warranty, cheap boiler, and I expect to replacement them at the first failure beyond the warranty period. As such they cost me around £80pa, but my installation cost is effectively zero).
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By rikur_
FLYER Club Member  FLYER Club Member
#1884621
Big Dex wrote:Best advice I can give (based on my personal opinion); stay away from Heatline, Biasi, Vokera, Main, Keston and Potterton boilers. Vaillant or Veissman are my personal preferences, and Alphas in rental properties .

Thanks for the insight. I've avoided all on your avoid list. Gas Vaillant in one house, Oil Grant in the other (albeit that's largely a back-up system now to the air source)
#1884633
A Potterton (oil) I removed lasted 35 years and a twelve year old could maintain them. I gave it away to a builder who was very keen to get it. There was no problem with it - I put in a condensing one which I may live to regret. As for the plumbers who put in my late F.I.Ls CH system - I wouldn’t let them change a bliddy tap washer.
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