glowworm hxi

[buckley plumb]

had look at this last night the hxi with orange display . boiler fine in max rate but in low rate it screams like a jet engine.tried the off set but no joy it sent analyser bleeping.spoke to glowworm who said poss gas valve - but i thought gas valve just opens and fan pulls the amount of gas through req .tech telling me gas valve modulates ? would it be fan or gas valve

 

[lame plumber]

give the solenoid a tap. try setting co2 levels correctly in low rate, if you cant then probably the valve jamming, esp if the fans working ok at max rate and levels ok.

 

[buckley plumb]

give the solenoid a tap. try setting co2 levels correctly in low rate, if you cant then probably the valve jamming, esp if the fans working ok at max rate and levels ok.

thanks will try . i did try setting co 2 but levels were high and wouldn't stabilize .am i right thinking gas valve does not modulate .suppose the valve could be stuck or chattering

 

[dave1]

They can be tricky to set up, and the analyser freaks out and takes about 3 years to get back to normal levels. I use an Anton and don't rate them, as like I say it doesn't like high levels of co.

 

[ambrosia]

if its the gas valve which is faulty why is it screaming like a jet engine, (i'm guessing its the fan thats making the noise)

did you gas rate it on high flame, is it burning to max kw

 

[mountainman]

Not the fan mate, incorrect air/gas ratio can make the boiler surprisingly noisy.
Sometimes the gas valve cannot be adjusted enough to stop the noise.

 

[buckley plumb]

if its the gas valve which is faulty why is it screaming like a jet engine, (i'm guessing its the fan thats making the noise)

did you gas rate it on high flame, is it burning to max kw

fan not noisy on max and analyser readings at max are spot on and gas rate. just min rate definitely mixture problem but i thought gas valve is just an open close valve .readings ruined my anton analser spent nearly an hr trying to set

 

[buckley plumb]

Not the fan mate, incorrect air/gas ratio can make the boiler surprisingly noisy.
Sometimes the gas valve cannot be adjusted enough to stop the noise.

is it normaly the gas valve mate and how can i set new valve up without ruining analyser

 

[dave1]

Think you just need to set it up on min rate, trouble is the analyser. You could try adjusting then putting the analyser in then removing quickly if it's far out. Then keep trying.

 

[jtsplumbing]

Have you set the boiler in service mode ? on glow worm display needs to flash, had the same a few mths back , it was low rate causing the noise.

 

[Leo21]

Is it a Honeywell gas valve? This has happened on a few new Vaillants. Exactly the same symptoms, faulty gas valve.

 

[buckley plumb]

Is it a Honeywell gas valve? This has happened on a few new Vaillants. Exactly the same symptoms, faulty gas valve.

not sure leo mate its the older hxi about 4 years old now .was just wondering how gas valve could cause this as thought it was just open or closed valve .

 

[buckley plumb]

Think you just need to set it up on min rate, trouble is the analyser. You could try adjusting then putting the analyser in then removing quickly if it's far out. Then keep trying.

spent an hr trying to set it up on min going back with gas valve I think

 

[buckley plumb]

Have you set the boiler in service mode ? on glow worm display needs to flash, had the same a few mths back , it was low rate causing the noise.

yes set in service mode low rate it was noisy in service mode low or when boiler modulated to low . and when I say noisy 20 sec in there and my ears realy hurt . had then noisy before and adjusting them cured it . but this one still the same - my main question is that I thought the gas valve was just an open close valve and the fan draws the gas like most forced burners anyone confirm this - all I can think is the valve is not fully opening as some have stated on here causing the mixture not to adjust enought

 

[Leo21]

not sure leo mate its the older hxi about 4 years old now .was just wondering how gas valve could cause this as thought it was just open or closed valve .

Its not though, it's modulated by a governer which is reliant on fan speed.

 

[dave1]

Have you checked the fan speed?

 

[Leo21]

Have you checked the fan speed?

How do you check fan speed?

 

[Ermintrude]

Stick your fingers in.

 

[dave1]

How do you check fan speed?

Yep pretty sure you set the fan speed up on one the boards.

 

[jtsplumbing]

Download installation instructions, on page 33 it will tell you how to set fan speed and what speed fan should run at, just need to drop control panel and use small screwdriver.

 

[buckley plumb]

fan speed ok you can check in service mode so going with gas valve let you know how I get on

 

[dave1]

Good luck, look forward to hearing the outcome.

 

[Leo21]

fan speed ok you can check in service mode so going with gas valve let you know how I get on

It will be the gas valve.

 

[buckley plumb]

gas valve fitted and now quiet . setting up a bit hit and miss at first but it now sets in low rate .