Boiler wont ignite after power off

G

gavc

Messages

20

• Jun 8, 2019

• #1

I replaced a couple of TRVs earlier, and prior to starting I powered off the boiler (a Main Heat 15). Boiler is 7 months old, and never been isolated from the mains before today.

Once all the rads were bled, went to power on the boiler and now the pilot won't ignite. And the reset button doesn't do anything.

As a total novice I'm not intending messing with anything, but does anyone have any suggestions?

Thanks

 

B

Brambles

Esteemed

Messages

873

• Jun 8, 2019

• #2

Do you have the same issue for Hot Water and Central Heating? Or is Hot Water only ok? If it is both not functioning:

Is this operating on a sealed system?

If so:

Check that you have properly repressurised the system - it needs to at least 0.5bar

Check that you have power to the boiler.

Follow the reset procedure ( it is very simple) set out in the users manual - but you need to follow the precise process to ensure that the boiler has reset.

If it is only not operating on heating:

The motorised valve (s) would be my first point if call to find the fault.


Thereafter, if no success you need a Gas Safe Engineer to look at it

 

G

gavc

Messages

20

• Jun 8, 2019

• #3

Hot water seems OK, that seems to be the only the pipe that gets hot. Though I can't see the pilot light, so that's confused me..!

Yeah, it's pressurised OK, I took it up to 1bar.

 

A

Aire

• Jun 8, 2019

• #4

gavc said:

Hot water seems OK, that seems to be the only the pipe that gets hot. Though I can't see the pilot light, so that's confused me..!

Yeah, it's pressurised OK, I took it up to 1bar.

Click to expand...

It doesn't have a pilot light.

 

gmartine

Esteemed

Gas Engineer

Messages

2,363

• Jun 8, 2019

• #5

No pilot on modern boilers fella.

 

G

gavc

Messages

20

• Jun 8, 2019

• #6

Shows how much I know

 

G

gavc

Messages

20

• Jun 8, 2019

• #7

Think maybe I surpassed myself managing to replace the TRVs without flooding the house! Need to call in the experts to get it up and running in that case..

 

gmartine

Esteemed

Gas Engineer

Messages

2,363

• Jun 8, 2019

• #8

The heating wont come on if the thermostat isn't set high enough.

Set it on 25C and see if it fires up.

 

G

gavc

Messages

20

• Jun 8, 2019

• #9

Did try, but I'll give that another shot..

 

ShaunCorbs

Super Moderator

Staff member

S. Mod

Plumber

Gas Engineer

Subscribed

Messages

34,632

Solutions

1

• Jun 8, 2019

• #10

Is the pump running / can you hear it running

 

G

gavc

Messages

20

• Jun 8, 2019

• #11

The pumps actually a lot noisier than before, and it's getting hot (the pump) after 5 or so minutes.. But the rads aren't..

 

A

Aire

• Jun 8, 2019

• #12

Sounds like an airlock. Have you bled the pump or any airvents on the system? Have you bled the rads?

 

G

gavc

Messages

20

• Jun 8, 2019

• #13

I bled all the rads. Didn't know I could bleed the pump tbh..? Or anything else.

Now's when I wish I'd left it alone.. Obviously don't know enough about the system, and thought I'd be clever and replace the rad valves.

So.. I just bled the pump. No air in that.

 

Last edited: Jun 8, 2019

A

Aire

• Jun 8, 2019

• #14

Got a pic of your pump and all associated pipework?

 

G

gavc

Messages

20

• Jun 8, 2019

• #15

Just popped out for an hour will upload pic later. Cheers fellas.

 

B

Burger

• Jun 8, 2019

• #16

What motorised valve(s) do you have? You have opened the trv’s? Have you missed anything simple like the programmer? Also as per Craig, a photo at this point maybe good.

 

G

gavc

Messages

20

• Jun 8, 2019

• #17

I've opened the TRVs, programmer is all ok, think I did all the obvious checks.

As for the motorised valve, I think it's a 3 port, but will add a pic of that too. I think that was playing up before today, as when I had hot water only on, the upstairs rads were heating up.

Hope the pics help..

 

G

gavc

Messages

20

• Jun 8, 2019

• #18

...

 

A

Aire

• Jun 8, 2019

• #19

Always baffles me why installers are happy to replace the boiler and use the existing pump.
You could try turning your heating on, then using the speed selector on the side of the pump. By slightly turing it towards setting 2 but not actually going all the way, you'll hear the pump power off, do this for 10 seconds, then switch it back to 3 for 10 seconds, then off again and repeat for a fee minutes. If there is any air this could help dislodge it.

 

B

Burger

• Jun 8, 2019

• #20

Yes you have a 3 port valve. Select heating and feel the pipe off the port labelled a, see if it gets hot. If not try heating and hot water together and see if it gets hot.

 

G

gavc

Messages

20

• Jun 8, 2019

• #21

I'll give both of these a shot in the morning, thanks again all.

 

G

gavc

Messages

20

• Jun 9, 2019

• #22

OK, so I've tried both suggestions, thanks Craig and cbw.

Pipe A doesn't get hot in either scenario. Also, I'm not sure of the relevance, but there's no resistance on the lever on bottom of the 3 port valve, whether the heating is on or off..

 

M

Millsy 82

Plumbers Arms member

Plumber

Gas Engineer

Messages

4,350

• Jun 9, 2019

• #23

Is the pipe for B getting hot? If so note what cylinder stat is on then turn down to say 20 so it isolates that.

Have you adjusted the pump speed?

You have a bypass valve is that getting hot? Turn that off.

 

G

gavc

Messages

20

• Jun 9, 2019

• #24

Millsy 82 said:

Is the pipe for B getting hot? If so note what cylinder stat is on then turn down to say 20 so it isolates that.

Have you adjusted the pump speed?

You have a bypass valve is that getting hot? Turn that off.

Click to expand...

Pipe B. Nope.

I did try the pump at 2 setting for a while. No difference.

What's the bypass valve?

 

G

gavc

Messages

20

• Jun 9, 2019

• #25

Might be worth mentioning, when I said

"As for the motorised valve, I think it's a 3 port, but will add a pic of that too. I think that was playing up before today, as when I had hot water on, the upstairs rads were heating up."

That's no longer happening. The rads don't heat up at all now..