Gas boiler going burble

[Count Steer]

I noticed my gas boiler making hubble bubble* noises shortly after it kicks in first thing in the morning. System pressure was a bit low so I adjusted it. Checked a couple of rads and bled a couple + the highest point in the system (a towel rail) - no cold spots and not even a hint of air. It's a relatively new Worcester combi-condensing job and the system is Fernoxed and has a Fernox filter thingummy.

It may be that I haven't been stood near it at 6am before and it is only on start-up from cold.

Any thoughts?

Ta.

(It's on a service contract/warranty so I can tell them it's due a service visit if necessary and/or complain it's making strange noises).

* kind of 'gloop, gloop' noises.

[Mr. Dazzle]

Stand in a different room when it turns on.

[mangocrazy]

That sounds like air in the system (as you correctly diagnosed) and to be honest on startup after an overnight cool down there is always an element of that. It might be worth checking if your boiler has a bleed vent on it's top plate (our Intergas has one) so you can remove any air trapped within the boiler. As yours is a combi I'm assuming you don't have a DHW cylinder, so no need to bleed that circuit (as there isn't one)...

[Count Steer]

That sounds like air in the system (as you correctly diagnosed) and to be honest on startup after an overnight cool down there is always an element of that. It might be worth checking if your boiler has a bleed vent on it's top plate (our Intergas has one) so you can remove any air trapped within the boiler. As yours is a combi I'm assuming you don't have a DHW cylinder, so no need to bleed that circuit (as there isn't one)...

Cheers. I'll check for a boiler air bleed vent. (The previous boiler had a pressure vessel at the top that an engineer drained iirc but he definitely depressurise it with a foot pump!.

Yes, there's not hot water tank.

I have wondered why noone has invented a device to scaveng air out of a system - it doesn't seem like a difficult thing to do.

[Mr. Dazzle]

I have wondered why noone has invented a device to scaveng air out of a system - it doesn't seem like a difficult thing to do.

My boiler circuit bleeds itself, it's got a valve by the hot water tank that occasionally gives a little hiss when certain valves (i.e. the ones which open/close to control which bits of the heating or how water are on) close.

https://www.screwfix.com/p/worcester-bo ... lsrc=aw.ds

[mangocrazy]

To be fair, you'd need auto bleed valves at a number of places in the system as there are a number of high spots where air can get trapped. It's normally only a problem if you have a small but undetected leak where air can constantly bleed into the system (as water bleeds out). Auto bleed valves can and do fail, as well.

[Mr. Dazzle]

The fact that mine still gives off the occasional hiss demonstrates they're not 100% effective right out of the gate

It's also not located at the highest place in the system

[Count Steer]

I'll hand in my man card and read the manual later.

Oddly enuff I heard two women discussing their boiler woes on Wednesday.

'Boiler has stopped working, the house is freezing. I phoned the service people* that I've been with for years. They said they could fit me in on the 14th January'.

'Oh, I'm with the same lot and I need them to attend to mine too'.

Some service contract! It's going to be a merry Christmas.

* This is a biggish, local, independent outfit. Fortunately I'm not with them.

PS A quick Google also says gurgling can be caused by a frozen condensate pipe. Not had a problem before and it's been colder than this but I'll investigate....or see if it stops when the weather warms up a bit. I'd expect it to gurgle constantly though or, more likely chuck out an error code and stop working.

[mangocrazy]

In this cold weather the most common cause of boilers failing is not actually the boiler itself, but the condensate discharge pipe freezing up and backing up. When the boiler can no longer get rid of the condensate it just stops working. The code of practice has changed in recent years to stipulate much larger condensate pipes and where and how they feed into mains drainage, all to lessen the risk of freezing.

[Count Steer]

In this cold weather the most common cause of boilers failing is not actually the boiler itself, but the condensate discharge pipe freezing up and backing up. When the boiler can no longer get rid of the condensate it just stops working. The code of practice has changed in recent years to stipulate much larger condensate pipes and where and how they feed into mains drainage, all to lessen the risk of freezing.

Mine runs into a soakaway container full off alkali - the condensate is acidic.

I've got a few 'war stories' of when condensate boilers were introduced - of the testing before appliance approval. We put a few in employee homes - including the Chairman's. One of my team was on dedicated standby in case he had problems...and he did...with a frozen condensate pipe. Cue young Graham making a late night mercy dash, walking into the Chairman's house and leaving a trail of dog shit behind him. I think the bosses dog had left a present for him.

Another involved injecting a jolt of refrigerant gas into a test house and collecting samples of condensate, which turned black as the heat exchanger started to dissolve. Chloro-fluoro hydrocarbons + moisture, heat and an active surface = HF and HCl. Which was also why we could sweep the remains of the heat exchanger out of the boiler at 'Knobs and Knockers' where they used solvents to degrease brass door furniture.

Eeeh, them were t'days when I had a proper job. .

[mangocrazy]

In the early days of condensing boilers, quite a few boiler manufacturers just re-purposed their existing aluminium or steel heat exchangers. As you say, condensate is acidic even if only mildly and munches its way through ali and steel very happily. The only viable materials for heat exchangers in the condensing age is stainless steel or copper.

Injecting a jolt of refrigerant gas into a test house sounds like a lot of fun...

[Count Steer]

In the early days of condensing boilers, quite a few boiler manufacturers just re-purposed their existing aluminium or steel heat exchangers. As you say, condensate is acidic even if only mildly and munches its way through ali and steel very happily. The only viable materials for heat exchangers in the condensing age is stainless steel or copper.

Injecting a jolt of refrigerant gas into a test house sounds like a lot of fun...

We just opened a cylinder of gas in the test house kitchen while the boiler was running (it was the 80s).

The thing was that the worthies at the research station didn't believe us about the HF and HCl so I sent them the condensate chromatography traces with thumping great F and Cl peaks in. 'Oh no' they said 'they're just small aliphatics'. So they ran some more tests and then got the screaming abdabs about condensate disposal + aerosols and kitchen air quality etc. Me and young Graham caused quite a stir.

[Count Steer]

Not totally unexpected, but this morning the boiler kicked in at 6am....and switched off/declined to ignite with an error code soon after. Reset it. Nope. Went through the steps as guided by the app. Nope.

(I went around the house and bled everything yesterday, not a sniff of air in the system).

BG engineer arriving tomorrow morning.

(Then the streamer had a hissy fit, errored and needed a reboot when I put the radio on).

[mangocrazy]

Not totally unexpected, but this morning the boiler kicked in at 6am....and switched off/declined to ignite with an error code soon after. Reset it. Nope. Went through the steps as guided by the app. Nope.

(I went around the house and bled everything yesterday, not a sniff of air in the system).

BG engineer arriving tomorrow morning.

(Then the streamer had a hissy fit, errored and needed a reboot when I put the radio on).

Dunno about where you are but temps are at least 10 deg C higher than yesterday, so the the boiler picked an optimum date in late November to go pop. What make is it and what's the error code? If it's anything like most boiler failures I've suffered in the past, it's either the fan or the gas valve gone rogue.

[Mr. Dazzle]

Mine had the same sort of error, then nearly killed me with a CO leak

From the sound of it up there ^^^, Count is well versed in boilers leaking gaseous nasties though

[Count Steer]

Not totally unexpected, but this morning the boiler kicked in at 6am....and switched off/declined to ignite with an error code soon after. Reset it. Nope. Went through the steps as guided by the app. Nope.

(I went around the house and bled everything yesterday, not a sniff of air in the system).

BG engineer arriving tomorrow morning.

(Then the streamer had a hissy fit, errored and needed a reboot when I put the radio on).

Dunno about where you are but temps are at least 10 deg C higher than yesterday, so the the boiler picked an optimum date in late November to go pop. What make is it and what's the error code? If it's anything like most boiler failures I've suffered in the past, it's either the fan or the gas valve gone rogue.

It's a newish (under warranty) Worcester and it gave an ignition failure error (EA 227) - which is pretty generic as it won't ignite if something is wrong but it doesn't tell you what that is....however, there are 3 prime suspects, 2 of which I've eliminated (blocked flue, system pressure), will check the 3rd later.

Chances are the engineer will plug his laptop into the diagnostic socket and go 'Aha!'.

[mangocrazy]

Not totally unexpected, but this morning the boiler kicked in at 6am....and switched off/declined to ignite with an error code soon after. Reset it. Nope. Went through the steps as guided by the app. Nope.

(I went around the house and bled everything yesterday, not a sniff of air in the system).

BG engineer arriving tomorrow morning.

(Then the streamer had a hissy fit, errored and needed a reboot when I put the radio on).

Dunno about where you are but temps are at least 10 deg C higher than yesterday, so the the boiler picked an optimum date in late November to go pop. What make is it and what's the error code? If it's anything like most boiler failures I've suffered in the past, it's either the fan or the gas valve gone rogue.

It's a newish (under warranty) Worcester and it gave an ignition failure error (EA 227) - which is pretty generic as it won't ignite if something is wrong but it doesn't tell you what that is....however, there are 3 prime suspects, 2 of which I've eliminated (blocked flue, system pressure), will check the 3rd later.

Chances are the engineer will plug his laptop into the diagnostic socket and go 'Aha!'.

Yes, doubt it will take long to track down. I'd also add the oversize 'spark plug' that ignites the air/gas mixture as a possible culprit, although they should last until well out of warranty.

[Count Steer]

Dunno about where you are but temps are at least 10 deg C higher than yesterday, so the the boiler picked an optimum date in late November to go pop. What make is it and what's the error code? If it's anything like most boiler failures I've suffered in the past, it's either the fan or the gas valve gone rogue.

It's a newish (under warranty) Worcester and it gave an ignition failure error (EA 227) - which is pretty generic as it won't ignite if something is wrong but it doesn't tell you what that is....however, there are 3 prime suspects, 2 of which I've eliminated (blocked flue, system pressure), will check the 3rd later.

Chances are the engineer will plug his laptop into the diagnostic socket and go 'Aha!'.

Yes, doubt it will take long to track down. I'd also add the oversize 'spark plug' that ignites the air/gas mixture as a possible culprit, although they should last until well out of warranty.

The other thing that used to go was the flame failure device (basically a thermocouple stuck in where the flame should be, you'll see them on the rings of a gas hob too, so if the flame goes out the gas should cut off). Two disimilar metals in a hot thing and things can migrate and they fail...but not usually that quickly!

My money is on the soakaway container is clogged and the pipe has gradually filled up, so I'll check it and refresh the limestone chippings anyway. If that's OK I'll wait for the van.

Fortunately we have umpteen fan, panel and other heat sources (pessimist? Moi?) but we'll be having a sponge bath tonight.

Oh, PS, the last time I had to call them out (for the old boiler) the engineer, who was a couple of days off retiring, thought his mates had set him up. A bluetit had evaded the cover mesh on the flue and though 'Ooh, prefab nest!'....and promptly died in the flue.

[mangocrazy]

My first encounter with backed up condensate overflows was in January 2007. I'd just flown back from a Philippine holiday in the tropics over Christmas to be confronted with a freezing cold house and a boiler that refused to work. Once I'd been informed of what the problem was and its comparatively simple solution that was always the thing I checked first...

[Count Steer]

My first encounter with backed up condensate overflows was in January 2007. I'd just flown back from a Philippine holiday in the tropics over Christmas to be confronted with a freezing cold house and a boiler that refused to work. Once I'd been informed of what the problem was and its comparatively simple solution that was always the thing I checked first...

Well, I've been out and lifted the cover off the soakaway pod. (It's by the path outside the kitchen door. When the chaps relaid the path I asked them to put a cover over it, thinking of a small, plastic, round drain-rodding type thing. They put a full sized, rectangular, metal one. Good place to park the kitchen waste bin/stash contraband in though ). It's fine at that end of things, still some limestone in there. Got a few fine roots too, but that's in the nature of things. Filled it with water to see how fast it drained, just out of curiosity. It's definitely not fast but I broke up the chips a bit and pulled out some rootlets - I'm pretty sure it's not the issue, there's also 2m+ of 1"+ pipe between it and the boiler. I know CH⁴ + 2O² = CO² + 2H²O* - but it's only going to be a trickle.

So, engineer's problem now.

*Hmm...superscript⁴ works....where did subscript disappear to?