GV-4 Ignition Issue

MONACO

Hello, I have (2) GV-4 boilers in my home. One is currently running, the other is not. The non-runner was working fine until a week ago when I changed out my indirect water heater. What I have done to get it back up and running is the following: I have taken the boiler completely apart and checked for any debris or blockages. It has been thoroughly vacuumed and all hoses & orifices checked for obstructions (none found). Ignitor replaced. A known functioning Control Module (1013-200) & Diaphragm Switch have been installed (these were taken from my other working boiler). Boiler goes thru the start-up sequence but when it gets to “Burner Flame Proven” (5th LED) it immediately shuts down and starts the sequence over. Never fires. I thought it might be an insect blockage issue but none found. HELP!!!

Jim “MONACO”

EdTheHeaterMan

Is the gas valve opening? If there is no gas, you can't get fire! Try putting all the controls from the defective boiler on the working boiler. that will tell you that the stuff you took off the defective boiler is working or if there is a problem with something.

Sometimes it is just something stupid like leaving a valve closed.

JUGHNE

I had one of these in my house and the loudest part of it was when the gas valve opened. A definite clunk.

Do you get power to the gas valve on the ignition try?

Or like Ed said, something simple…..

MONACO

Thanx Guys! The Gas Valve is not opening. There is no “Clunk” sound. Meter shows an “extremely” brief spike to 0.96 but that spike varies a bit each time I run the cycle.(Meter set at 200VAC). The original Honeywell Controller has been tried on the other “working” boiler but it does not fire that one, so I’m gonna replace it. The 1013-200 that was on the working boiler is now on the non-working boiler. All other components on this boiler are known to work (I pulled them off the working boiler). I have Not checked the exhaust elbow (with the condensate drain) for debris.

Jim (Monaco)

tim smith

high likelihood of heat x restriction on an older GV. You say you pulled apart and cleaned? Truly pulling these apart and cleaning is a bit of a pain. You need section assembly kits with gaskets x 4 for 1 of those boilers. Then totally dismantle boiler, pull cast block off base and split block. Rarely worth it on these as they are usually 20+ yrs in, cost doesn’t usually pencil. Hopefully something other than heat x obstruction.

MONACO

I’m sorry to have to keep re-hashing this but I have cleaned the boiler burner cavity out completely (I am not gonna tear it apart), seeing as this boiler was working fine a week ago and only stopped working because the control module crapped out (this is a known) I find it hard to believe there is any sort of obstruction. I have made sure the fan housing is totally clear. All components came off of my good boiler and are in working order (I have checked and rechecked) There is NO current going to the gas valve upon ignition. What is the mechanism (sensor(s) that triggers the current to go to the gas valve? Is it perhaps the rpm of the fan?

Jim (Monaco)

MONACO

Ohhh… I pulled the exhaust pipe attached to the exhaust elbow and vacuumed out elbow and all the tubing, too.

Jim (Monaco)

Jamie Hall

If there is no current going to the gas valve — and you have veriried, with an ammeter, that indeed there is no current going, then you need to go back and find out what is preventing that current from flowing. It is either a broken wire or a bad connection or it is not being commanded on. If you have voltage at the control terminals, but no current, it's either an open gas valve (you will have voltage at the gas valve) or a bad connection or broken wire.

Now if it isn't that, and make no assumptions, then the question becomes what determines if the controller should send voltage to the gas valve? Having figured that out, check all those conditions and any connections or wires involved, as well as any sensors or switches. Which is to say, with regard to your final question, what is the mechanism that triggers the controller to command the gas valve on. Make no assumptions: check everything in the chain. Wires, sensors, connectors. It is much more likely to be a mis-wired connection or a bad connector than anything else.

JUGHNE

The air pressure switch is normally open and should have the white hose on the front barb and the red hose on the back. There should be 5 hoses connected to the small plastic manifold.

Perhaps these are turned around somehow. IIRC there is a divider wall inside the manifold.

3 reds on the right and 2 whites on the left….looking from front of boiler.

FWIW

MONACO

I appreciate people trying to help me, but I’m getting the impression that some of you don’t really know much about an older GV-4. Both of my GV-4s have only 3 vacuum hoses (2 - a red & a white) that go to the pressure switch (mine are correctly installed) and there is another red one (3) that goes to the barb fitting on the gas valve. All these vacuum hoses come off the bottom of fan housing.

My main question: There is NO current going to the gas valve upon ignition. Igniter is new and functioning. What is the mechanism that triggers the current to go to the gas valve? Something must trigger the control module to send the power to gas valve. There are no sensors placed in the boiler cavity. Is it perhaps the rpm of the fan being read by the module?

Thanx! Jim (Monaco)

neilc

pressure switch has to prove

do you have your manual?

Jamie Hall

It could be a fan rpm sensor, though it's more likely to be a pressure switch sensing that the blower is on. It could be a stack temperature switch that's open. It could be a gas pressure switch that's open. If there is an automatic damper, it could be that isn't open all the way. It could be a spill switch open. Let's see… what other safeties might there be. Low water cutout? Might be open. Not seeing the unit, I'm not sure what all there might be.

Until you identify all of the safety devices on the unit and ensured that they are all correct, you haven't proved anything about anything.

JUGHNE

The GV -4 I speak of is a series 2 from 1995.

2 hoses on the differential pressure switch, one on the gas valve, one on the fan inlet flange.

They are all connected to a condensate trap which yours apparently does not have.

My book shows a single speed fan, on or off design.

A single stage non modulating negative pressure gas valve.

The ignitor is a combo HSI and flame sensor.

The pressure switch would have to close and remain closed for the HSI to glow and begin ignition sequence.

A volt meter across the switch should show 24 volts until the fan starts and closes it.

You could have a "hiccup" in the switch which would not let the gas valve open.

This is where an analog meter with swing needle would let you catch that. If it is the case. Digitals may not show you something that happens quickly.

Do you have the book for your series?

Note: all the vacuum hoses can not see the same pressure point as there has to be some differential between the sides of the pressure switch.

tim smith

Is it a series 1, 2 or 3? That will help as to which manual to work from. Does the igniter ever get power? Have you tested across the contacts on pressure switch when going for trial for ignition. Pressure switch has to be closed for it to continue to igntion, ie open gas valve.

tim smith

Here is a gv boiler series 1 pressure switch testing procedure from their control supplement. Service control supplement attached along with excerpts from it I think may be applicable. Page 8 is flow chart then page 6 is where your symptoms direct you to. Also attached complete control supplement for series 1, think maybe for series 2 also but not 100%.