Hi Folks
First post - I've searched to see if this one's already been covered, but can't find anything, so here goes...
I have a 5yo 30sxi boiler that provides CH and HW via a megaflo cylinder. All has been well for the last few years or so, but recently I suffered from the burner gasket breakdown issue, which killed the internal expansion tank. I replaced the tank, and the gasket (the burner cover had slightly warped but a good tighten on the flange nuts closed it off), and all has been well for 10 months or so.
Now the latest issue is this - on ignition, there's a distinct 'flutter' or shudder even, that can be heard all through the house. I have read that a poor mixture can cause dodgy ignition, so I've just opened the covers and checked the fan, and gas valve voltages. The manual states that both should be at 24v. The valve is at 13v and the fan at 30v. Methinks that something is amiss, as I thought gas pressure was modulated by fan speed so I'd expect both these values to be within limits. My understanding was that on demand, both levels should be 24v and fan speed was controlled through the additional wires on the fan connector.
Has anyone else had experience of this?
Could it be the gasket failing again, causing the poor mixture?
Could the fan and valve voltages point to another issue, or are they normal?
Am I completely off the mark?
Many thanks
John
First post - I've searched to see if this one's already been covered, but can't find anything, so here goes...
I have a 5yo 30sxi boiler that provides CH and HW via a megaflo cylinder. All has been well for the last few years or so, but recently I suffered from the burner gasket breakdown issue, which killed the internal expansion tank. I replaced the tank, and the gasket (the burner cover had slightly warped but a good tighten on the flange nuts closed it off), and all has been well for 10 months or so.
Now the latest issue is this - on ignition, there's a distinct 'flutter' or shudder even, that can be heard all through the house. I have read that a poor mixture can cause dodgy ignition, so I've just opened the covers and checked the fan, and gas valve voltages. The manual states that both should be at 24v. The valve is at 13v and the fan at 30v. Methinks that something is amiss, as I thought gas pressure was modulated by fan speed so I'd expect both these values to be within limits. My understanding was that on demand, both levels should be 24v and fan speed was controlled through the additional wires on the fan connector.
Has anyone else had experience of this?
Could it be the gasket failing again, causing the poor mixture?
Could the fan and valve voltages point to another issue, or are they normal?
Am I completely off the mark?
Many thanks
John