Problem with new Intergas HRE 18 OV not heating radiators properly

[Geoffuz]

Afternoon all,

I've read plenty on here bout Intergas boilers, but nothing i'm afraid that has helped me, so i'm reaching out!

In summary: I have a new HRE 18 OV boiler fitted on a Y plan system.
Boiler ground floor.
Cylinder and (new) pump directly above on 1st floor.
Feed/expansion tank directly above that in loft.
Wall stat; cylinder stat; pump and timer are all wired via a wiring centre.
TRVs on all but two rads (bathroom and hall)
3 bed Semi detached house with Lounge and dining room.

Issue is that when the boiler is set to heating, it lights and stays lit as normal, but the output appears to be very low and it takes an age for any heat to develop, particularly downstairs.
where they remain mostly lukewarm.
The sytem has been flushed and dessludged and flushed clean twice over and inhibitor added.
we have bled it to death and there are no cold rads or cold spots, just uniform insufficient heat.

The link between 9 and 10 on the low voltage side remains and the link between 6 and 7 has been removed (as per the tech support at Intergas).

When you add extra demand to the boiler for Hot Water everything warms up much quicker.

Also, out of pure interest, I put the link back in between 6 and 7 and the thing heated up in quick time, all the rads nice and toasty. I thought I had nailed it, but when I knocked the wall stat down to 12c when going to bed (I don't normally do this, I rely on the time clock, but it's for convenience at the moment) the boiler ran on for about 20 seconds, seemed to overheat a bit and shut down.
I was tired so I went to bed and thought nothing of it until I got up this morning at 6 am to have a waz and the rad was warm in the bathroom. I checked the airing cupboard and everything was red hot.
So I went down stairs to discover the boiler was on. I watched it for 5 mins and it shut down again, after what appeared to be a similar overheating thing to the night before.

My guess was that with the addition of the link on 6 and 7, whilst the wall stat had shut the pump down, it hadn't shut the boiler down. As such I removed the link and i'm back to square 1.

Any suggestions on this would be greatly appreciated as my fitter (who's a family friend) and I have gone through pretty much everything we can think of.

I saw in another post, someone had added a link between 4 and 5 and that did something. Wondering whether to try that next!?

Thanks in advance.

G

 

[Madrab]

How about getting the guys who installed it back in? All that playing about could potentially cost you a new boiler.

Sounds like you may have a circulation issue - what is the pump set to? - or the boiler isn't set up properly.

 

[Geoffuz]

Hi, thanks for taking the time to reply.
Yes, hes been back several times and we're scratching our heads now.
The pump is a brand new Grundfos Alpha 1 and we've had it on 2 and 3 so it's not that.
The display on the boiler control panel never goes off 5 so that says it's not hitting target temp and it's almost like it's in some throttled mode.

Very weird!

G

 

[ianmcd]

The ON demand should go to no1 on X2 and the link at 6 and 7 removed, post a pic of your actual wiring

 

[CBW]

Have you checked the 3 port valve? You mentioned that it seemed to work better with hot water on as well.

 

[Nige F]

Not being funny but, is the timer/programmer a 2 channel one ? A M8 had an ancient boiler (that I installed in the 70's) replaced a few years ago with a condensing heat only o.v one - used new 1 channel programmer and threw the perfectly good one awaay

 

[Geoffuz]

Hi all, thanks for taking time out your Friday night - much appreciated.

The switched live is from terminal 1 on 230v side and the 6 and 7 link is gone.

The mid position valve is new and working properly.

The timer controls the hw and heating independently and it's wired as the manual says.

I checked all the parameters and they all match the factory ones.

I'll attach a picture.

Thanks folks

 

[ianmcd]

what controls are you using ? i.e. thermostat external programmer ?

 

[Geoffuz]

Hi there,

It's a programmable room stat centaurstat 7 which im currently just using manually and the timer is an Icon which is currently locked on heating (ignore clock as haven't set it whilst im having issues).

Thanks for your help

 

[ianmcd]

Did you go into the boilers parameters and set the internal timer to off ?

 

[CBW]

Has it been balanced correctly?

 

[Geoffuz]

Hi folks, the balancing was pretty good with the old boiler, bar the last rad on the circuit which was always slow to heat up. I've dialed the upstairs lock valves down a touch to help, but it's painfully slow to heat up.
Re the internal timer, I've got it on "C-on" as opposed to "t-on" which is the inbuilt clock so i assume that renders the timer defunct?

Thanks again

Geoff

 

[BlueLoo]

The pump is a variable speed pump (or at least thats what the literature says)

If this is a swap out, old-new, do you have the boiler bypass still?

If you do, what is it? A automatic bypass valve or a valve just left open?

(I read you have a Y plan but its still worth asking )

 

[Geoffuz]

Hi Blue, there's no bypass, just two rads with no trvs. It's an old system that was originally conceived for a back boiler in (i guess) the early 80s. I had that boiler replaced with a Worcester bosch 14/19 cbi with a new cylinder and a y plan in 2004.
It's chugged along happily until about a month ago when the heat exchanger developed a leak.
I'm guessing that now the old infrastructure is sending signals to the new super sensitive boiler, that's screwing things up.

Progress eh!

Thanks

G

 

[BlueLoo]

Hi Blue, there's no bypass, just two rads with no trvs. It's an old system that was originally conceived for a back boiler in (i guess) the early 80s. I had that boiler replaced with a Worcester bosch 14/19 cbi with a new cylinder and a y plan in 2004.
It's chugged along happily until about a month ago when the heat exchanger developed a leak.
I'm guessing that now the old infrastructure is sending signals to the new super sensitive boiler, that's screwing things up.

Progress eh!

Thanks

G

Ah.

Progress is good but more complex systems have more complex problems

With it being new, i wondered if the installer had fitted a bypass fully opened (Y plan not withstanding).

Hope you get an answer.