Worcester 280RSF overheat thermostat tripped, help please

[ChrisOxford]

Hello,

My 1995 vintage Worcester 280 RSF stopped working (pump runs but not fan and so no ignition), and I've found that the overheat thermostat had tripped.

Resetting it got things working, but I have a feeling it will trip out again unless I find the actual cause.

Are there any stock faults on this range of boilers, before I knuckle down to a serious testing and fault finding session? It would be really handy to have a few ideas of likely suspects to check.

Cheers,
Chris

 

[boilerdoktor]

its a temp stat that knocks it out! also if the stat keeps popping it will weaken it! so its a heat issue ( not getting away from boiler)

Normally the prob lies in sludge in system/pump etc.

I would treat with x400/800 maybe change pump and stat and this little baby will run forever!

If your gassafe reg also check the gas valve is modulating up and down and not staying on high fire all the time!

 

[gremlin16]

this little baby will run forever!

Thats why WB don't take 'em on any more. Obsolete, and parts unobtainable, well according to the wonderful WB team.

 

[boilerdoktor]

this little baby will run forever!

Thats why WB don't take 'em on any more. Obsolete, and parts unobtainable, well according to the wonderful WB team.

Would you take a boiler on contract that is 10-17 yrs old??? no didnt think so!

240 and 280's are still ON with WB and supported on contract! fact

they will not take a boiler on that is 10 yrs old or more BUT if they have it on contract before its 10 yrs old..it stays on contract FACT

They still go out and repair 240 and 280 for a fixed fee!=-FACT

This is in line with ALL manus-FACT

Get off your wb hatefull horse! are you an ex engineer with an axe to grind?????

 

[gremlin16]

Get off your wb hatefull horse! are you an ex engineer with an axe to grind?????

NO, just an installer that cares for his customers.

What I am is a mature installer that cant be bought by freebies, nights out and well rehearsed sales talk. Must say their reps think their gods gift, shame they are such blatant liers.
As for 3% failure rate, thats another WB under estimated sales patter.
Its a lot higher FACT

WB are crap and and any self respecting installer just dont fit them. Most of WB installers only stay with them 'coz they know no better, and have no intention of ever going back to service them. As for breakdowns who cares a f**K WB will repair any thing, they dont want a bad name do they. (that came off one of their own engineers)

Being WB accredited mean sod all.
So you chuck in a load of WB so called boilers, WB sales are up, you are an unpaid sales man for WB. Unfortunately its the customers that suffer, but what do you care. WB are loosing sales at an alarming rate, FACT
Wise installers are going else where but WB reps are still out there preaching, but the wiser installers have already move on.

Walked away from WB about 4 years ago and can honestly say we dont miss a night sleep anymore.

 

[Agile]

WB are crap and and any self respecting installer just dont fit them. Most of WB installers only stay with them 'coz they know no better, and have no intention of ever going back to service them. As for breakdowns who cares a f**K WB will repair any thing, they dont want a bad name do they. (that came off one of their own engineers)

Most WB installers only fit their boilers.

Thats for two reasons ( sometimes three ).

1. Its a well known and advertised name so customers like them

2. The discounts/warrantee years are only available to those who shift a lot of their boilers. ( Called locking in! )

3. Some have little/no experience of fitting other makes so they dont even try to.

 

[ChrisOxford]

Thanks for replying everyone, especially Boilerdoktor!

Interesting politics too... I have to say that I've been delighted with the boiler. This is only the 6th breakdown in 16 years which I think is a good record. And I've been able to fix all the faults myself with a bit of help from people here (seem to remember you, Agile), and the excellent manual (dead programmer, diverter valve motor open circuit, expansion vessel diaphragm leaky, fan bearings dry, ignition board faulty and not sensing that pilot had lit).

The only time alarm bells rang was when our installer tried to push us into getting an oil rather than gas model, even though we're in a city and the house already had a gas supply! I seem to remember seeing some kind of incentive for installers to do this, being pushed by WB

Anyway, back to the fault... any more suggestions please? The rads certainly seem incredibly sludge-free (it's a sealed system and inhibitor has always been used), and the water was crystal clear when I drained everything last year to replace a faulty filling valve.

I read somewhere that the water-water heat exchanger could be scaled up. Thoughts anyone?

Thanks,

Chris

 

[boilerdoktor]

Get off your wb hatefull horse! are you an ex engineer with an axe to grind?????

NO, just an installer that cares for his customers.

What I am is a mature installer that cant be bought by freebies, nights out and well rehearsed sales talk. Must say their reps think their gods gift, shame they are such blatant liers.
As for 3% failure rate, thats another WB under estimated sales patter.
Its a lot higher FACT

WB are crap and and any self respecting installer just dont fit them. Most of WB installers only stay with them 'coz they know no better, and have no intention of ever going back to service them. As for breakdowns who cares a f**K WB will repair any thing, they dont want a bad name do they. (that came off one of their own engineers)

Being WB accredited mean s** all.
So you chuck in a load of WB so called boilers, WB sales are up, you are an unpaid sales man for WB. Unfortunately its the customers that suffer, but what do you care. WB are loosing sales at an alarming rate, FACT
Wise installers are going else where but WB reps are still out there preaching, but the wiser installers have already move on.

Walked away from WB about 4 years ago and can honestly say we dont miss a night sleep anymore.

dear dear! you are an andry man!!

the 3% failure rate is the number of breakdowns (due to boiler faultnot end user cock ups) for my instalations over a five year time frame!

i'm stating fact nothing to do with wb I make a tidy living as a "salesman" because f the products reliability I get a large percentage as recommends (friends and family)

Yes I do fix and service boilers I put in! I've got 240's and the like on contract with me who have been for 15 yrs!

So you are guessing about me, taking a stab in the dark, is this what you do in life?????

save your venom for the lads who hang around HRPC for six hrs of the day slagging off WB and vaillant! telling everyone who will listen that alphas and biasi are the dogs........

 

[gremlin16]

hang around HRPC for six hrs of the day

Sorry to hear you spend so much time in HRPC, things must be quiet with u.

Never mind, put your spare time in exploring the better range of boilers, that way you will not have to visit HRPC so often.

 

[ChrisOxford]

Just done some tests on the DHW side of things:

The modureg's spindle was nice and free when I popped off the cover. Turning on a hot tap to maximum flow, there's 21V being supplied by the Main Driver Board to the modureg coil which gives a burner pressure of 13mbar. If I turn the flow right down, the voltage drops to 9V and the burner pressure to 3mbar. These figures seem to agree with the MI ones, so I reckon the sensors, main driver board and modureg valve are behaving. I've also checked removed, cleaned and applied fresh thermal paste to the DHW and CH sensors.

The OT hasn't tripped out again, but while running a bath last night I noticed that the burner went out and the fan went off for about a minute before the ignition sequence kicked in again, which seems to be the "primary protection during DHW demand" which the MI says happens if the primary temp exceeds 90 degC.

So should I be considering a new water-to-water HE? Next prob is that mine is an early model (MI dated Jan 1994) with a cylindrical HE whereas the MI on the WB site is dated Feb 1997 and shows a flat box-shaped HE which is the only sort that seems to be available nowadays. Are they interchangeable? They certainly seem to be supplied with a handful of pipes.

CH seems to work nicely but haven't tried for more than 5 minutes as it's been 25 degrees here today, and the fault showed on DHW originally.

Thanks guys,

Chris.

 

[Blooflame]

As the good doktor said, it'll prbably be the pump. Try it with central heating.... after you turn it off does it lock out / overheat?? Usually the secondary heat exchanger get crpped up with sludge.

WB seem to be installer friendly when it comes to er...installing!! Support and parts are very good so personally I've no axe to grind there.

Hope you get your issues sorted

 

[ChrisOxford]

Fault only seems to occur on DHW, not managed to get it to fault on CH.

Pump overuns (and rads get a bit warm) after DHW demand stops, as normal.

So worth trying a new secondary HE then?

 

[petit_pablo]

So worth trying a new secondary HE then?

Worth a punt especially as you are in a hard water area.

Boilerdoktor you are a very angry person - FACT

 

[ChrisOxford]

Finally got myself a new water-water HE kit, which contains a new-style "Alfa" plate HE plus the necessary pipes etc. to install it in place of the obsolete white enamelled cannister HE.

The old one came out easily enough, and I've removed the 2 circlips and bracket around the primary connections, ready to fit the new parts. I've also got a new O-ring for the expansion vessel which has to be removed to access the HE.

As you'd expect, there is a bit of sludge evident. Can I take the opportunity to flush the boiler's pipework (aka "water flow manifold"), (most of) the diverter valve, the pump and the gas-water HE by connecting my garden hose (and a drain hose into a bucket) to the connections where the W-W HE goes? Am I correct in thinking that the diverter valve will already be in the DHW position when de-energised?

I realise I'd have to cap off the expansion vessel's connection (or refit the EV). The rads and pipework were drained and flushed (and inhibitor added) last year so I don't intend to do them again unless I really have to.

Haven't forgotten the pump as a possible suspect too.

Thanks again for everyone's advice.

 

[ChrisOxford]

Any ideas, people?

Got to fit the HE and get things up and running again tonight