parent without heating, viessmann

[adzz]

hi parent been without heating for over a week, can some one please help..

i have a viessmann vitoden 100, its an open vent boiler, well the hot water takes about 4-5 hours to warm up (should take 20-30 mins) and central heating comes on sometimes and is luke warm... i had british gas come out and they believed it was a sludge problem, so be parent folked out 500 to have the system flushed.. heating worked fine for 24 hours after flush, know the system aint heating up again (luke warm up stairs, cold down stairs) ... i think theres air block? but how do i solve this issue... i have bled the pump and rads a bit of air come out then water, .... any ideas thanks for you time

 

[diamondgas]

Hi adzz,

Personaly 1st thing you do is get back onto the phone to those who flushed the system, how long ago was that done? It may have nothing to do with them but I'd imagine you got some kind of guarantee yeh? Do your parents have a contract with BG? If so get them back out! There are many reasons why the circulation has stopped working correctly but you'll need someone to be checking out 3D not typing their thoughts here ... IMHO

 

[Paulus]

diamondgas is right. British gas diagnosed the problem and have charged for supposedly rectifying it. They have either mis-diagnosed or not done the job properly, it's down to them. Phone them up and play hell.

 

[adzz]

hi thanks for the advice, i got the flush done from an independent company only 5 days ago, theyve come back out and said there work is fine... i ve got bg coming out tomorrow, so i will update you when they diagnosed the problem... thanks

 

[REDSAW]

kerching££££.
try the pump or shut of all but one rad and see if it gets hot?.

 

[adzz]

hi BG come out today and they still cant diagnose problem, well i tryed shuting of all but one rad, which got fully warm ... so i countinued process radiator to radiator, all got warm indivdually... but when i open them all, it still luke warm. and water still taking hours to warm up, im total out of ideas.. any suggestions? also i put in a new pump when i got flush done... can it be a boiler problem? thank again

 

[stevetheplumber]

has anyone checked the gas rate ?had this scenario once and boiler was getting very little gas to use does boiler cut out ? does pump work list is endless for the symptoms youve given ring BG and ask for a manager to call

 

[adzz]

nope no ones checked the gas rate, the boiler cuts out every minute or so once the boiler think its reached temperature ie it will hit 65 and cut out and fall back to 40 and start up again every minute or so.. if the boiler stays on for 5 minutes everythings seems to work fine.. (happened after flush)... ( viseemann advice me it was a flow and return problem) pump is working fine... ive rang BG again after an eternity on the phone they have agreed to send someout tommorow...

 

[adzz]

im sorry gas has been checked, it was done via a flue test from bg... they said it was fine...

 

[< 0.004 = :-)]

have pump valves been fully re-opened after the pump was replaced ? is pump definately fitted right way round - is flow connection at boiler hotter than return ?

 

[tipintim]

Shut by pass down

 

[adzz]

the pump seems to be fitted the right way the pipes are all luke warm ....the flow is boiling hot and the return is luke warm on boiler... vissemann just adviced me that theres air in the boiler and i need to relese it? if so how do i do that on a viessmann vitoden 100?

 

[CMairiD]

Well, it sounds distinctly like issues we have with sludged up Viessmanns. If it is the early model WB1A (you can find this on the data badge on top of the boiler), then it has a paddle flow switch which is where the muck from the heat exchanger tends to congregate. Once that flow switch gets blocked, the boiler believes no flow and will shut itself down and never reach temperature. You'll get moderately hot flow from the boiler but almost no return.

If it's a system boiler, then you'll find the muck collects on the hose from the heat exchanger to the diverter valve.

Symptoms include poor heat to downstairs rads or in bad cases all rads, groaning pumps and if you watch the thermostat on the boiler, the numbers will jump in multiples of twos or threes, instead of rising by increments of one.

It is difficult to get the muck out of the boiler, even with a powerflush. We've had one recently where they machine flushed for most of the day, but still could not bring the boiler back up at the end of the day. It took a second flush of just the boiler to bring it back up. This second flush was connected with mains water to the flow and dumping out of the return, then swap positions for about six passes. Then connected the powerflush machine up to the heat exchanger for nearly two hours. Afterwards, we flushed through with mains again and were still pulling stuff out. Did manage to get the boiler back up and running, but it was a struggle and getting the air out of them is not the easiest of jobs.

If you do have the early model and you do have it flushed again, I can but strongly recommend you have a system filter, such as TF1 or Sentinel System Filter, cut in on your return to help catch any amount of crud that may develop over time.

 

[CMairiD]

Here's a video of the muck still in the HEX after a power flush and six passes on just the boiler through flow/return with mains water.

[video=youtube;jQ3GsgnlE2o]http://www.youtube.com/watch?v=jQ3GsgnlE2o[/video]

And another recently flushed. This is just the crud from the boiler! Nevermind the rest of the circuit.

[video=youtube;r-2uUKw7g2M]http://www.youtube.com/watch?v=r-2uUKw7g2M[/video]

 

[GasmanxxxR1]

Air lock?

Air locks can take days to sort out and can be a right pain in backside. had an issue the exact same as this one on wednesday.

 

[Resolute]

Air lock?

Air locks can take days to sort out and can be a right pain in backside. had an issue the exact same as this one on wednesday.

Your telling me! Yesterday I went to a seized tap spindle. Couldn't isolate the supply and had no bungs so drained down (waste of half hour), fixed tap in 10 mins then spent the next hour trying to remove the air lock!

Second time I've had a problem on a hot system where the CWSC isn't above the hot water tank and ive had to block the vent to suck the water through with a wet vac.

 

[armourer]

It seems to me reading through the posts BG diagnosed a blockage and recommended a power flush.
The powerflush was then carried out by an "independent" company?

The system them worked fine for 24 hours and faulted again?

Still showing signs of a blockage?

Sounds to me like the flush was not carried out correctly?
The fault lies with the company that carried out the flush not BG who's boiler cover you have or trying to take out?

 

[adzz]

hi thanks for the response im having the system drained down later today to have a look to see if theres sludge in the boiler, i have the wb1a model, is there anything else i should be looking out for on the boiler? i have a magna clean already installed that congregates alot of sludge,,

 

[adzz]

thanks cmairid ill have that taken a look at later today.....

 

[adzz]

hi ive had bg cover for about 2 years, i spoken to the company that removed the sludge there coming back again on monday, but today im having the boiler checked for sludge... so if there sludge in the system i can make them do a boiler flush...

 

[< 0.004 = :-)]

top post cmaird , was thinking blocked he if pump and boiler connections ok. op said its an open vent . did the older model not have the bleeding point with clear hose on top of the he?

when we done the course for the 100 , their engineer was saying when they asked for an open vent model for uk market the germans were freaked out

 

[CMairiD]

did the older model not have the bleeding point with clear hose on top of the he?

If it's there it's incredibly well hidden!

 

[< 0.004 = :-)]

never fitted the older so dono . one thing not to keen on the newer model is the casing can be pulled forward at the top when fitted. didn t think i d fitted it back right on one i d just checked, off/on/off/on. nah , still the same. had same boiler to check next day, walked in and exact same.
how old we talking with older models your seeing CmD ? open vent systems ?
seen similar shale type causing poor circ on sealed systems, both had burst coils in unvented steel cyls.
also had to cut out and renew pipework, rod 10mm hep with a wire coathanger blah to clear solid chokes . you done well getting those boilers going without being able to physically break up the deposits, it ends up setting like cement. you ever tried the heavy duty powder de scaler , used to be fernox ds-40 or something, acid basically , needs neutralised after. or adding x400 after you ve got them running and leaving for a few weeks and reflushing ?
these been fitted to unflushed existing or poor design causing it ?

 

[CMairiD]

WB1As were circa 2005-2007, at least that's when we were fitting them.

Most of the bother we are having are with OV, though have had one system boiler in a poor way. It was power flushed in March of this year with X800 and by October it was diagnosed with a choked HEX. Went to rig flush just the boiler itself and actually found the crud between the hose that exits the HEX into the diverter valve. The hose was so chokka that it was a bugger to release and manually clean. Instead of being flexible, it was incredibly rigid.

The first successful power flush we did was with DS 40 (and from information I gleaned on this forum ... thank you, thank you, oh wise forum friends!). Done in January 2010 and she is still running sweet as can be. Some of our systems had been done with X800 but had failed again less than six months. Because I wasn't party to the methodology of those X800 flushes, I can't say whether they tackled the problem in the right way or whether the DS 40 is the better chemical to use.

As far as fitting on dirty systems/poor design, it's a bit of both. I can't physically prove they were fitted on dirty systems, but engineering job notes show that they were aware of the problem and clearing blocked flow switches within 1.5 years after fitting.

Have a look at the cross-sectional diagram of the Viessmann HEX and then the semi-circular bits of crud manually flushed from the HEX only. Once that crap gets in the HEX and with the high heat, it's almost becomes welded to the surface and incredibly hard to shift it all.

 

[< 0.004 = :-)]

too true its a nightmare to remove it when its baked on hard, i m surprised anything but chems are doing the trick. not used 800 , only fast acting i think is any good is the acid , but can t always use it x400 is ok if theres still a wee bit circulation but usually needs at least 2 weeks with heating on normal settings to break down deposits in an HE. used to do maintenance for an HA, newer type estates, all with supremas. never been flushed when fitted, poor sys design as well, HE's used to choke up, short cycles ,whirl noise like a helicopter then the banging before cutting off. tenants used to phone in 2-3 weeks after we d added the x400 to say boiler has now quiet and heating ok so we d go back and flush out. you in a hard water area CmD ? soft water up here so not much experience with limescale, just wonder whats causing the on going problems your seeing. any chance the ov systems could be drawing air? worked with lads who wouldn t touch that sludged up filter. seeing your spotless manicured nail scraping around it was a bit different lol

 

[Mr E]

It sounds more like an airlock to me. Ring Viessmann Technical tomorrow for advice.

 

[CMairiD]

Hard water? 200 PPM in our area--hard as nails.

I am rather certain I know what's caused the majority of the problems: boilers going in filthy systems coupled with a healthy dose of design faults.

LOL about the nails ... they are no more manicured than yours, mate!

 

[RoryD]

has anyone checked the gas rate ?had this scenario once and boiler was getting very little gas to use does boiler cut out ? does pump work list is endless for the symptoms youve given ring BG and ask for a manager to call

Bang on Steve. that's what I'd have done