Glow Worm Ultracom 38cxi central heating problem.

[switchmode]

Only had the boiler in for one week and I am now finding that when the boiler starts to run on central heating the radiator icon is on the lcd display along with the water temperature and the burner flame status on the right hand side, all is ok untill the water temperature reaches the temperature set point and goes over by two degrees then the tap icon flashes on the display and the heating stops running, it then goes into some kind of internal circulation for a few minutes then fires up on heating again untill two degrees over and the same thing happen's again.
I have had no problems at all with the hot water.
any information would be appreciated on the problem.
Switchmode.

 

[twgas]

Have you looked at the manual to see if your symbols are normal? (I can't find a copy of user manual right now)

 

[mickyg]

Have a look in the manual, find the bit near the back where it tells you how to access "D" codes. then find out what reading you get for D41 and D40 whilst the heating is running and the burner on and close to max temp. Also how many radiators have you got?

 

[switchmode]

Thanks for the reply's,
to answer the first question yes all the icons look ok, but I am using the boiler with the climapro rf thermostat so some of the boiler display icons do not show only EXT, temp etc. the problem is still there without the climapro connected.
second questions, I have six radiators running on 22mm feed and return pipes to yorkshire manifolds feeding 8mm micro bore radiator pipes.these are the origional setup from my previous Y plan fully pumped system with a glo worm Majorca 346N (bring back a few memorys) my first thought with the 38 cxi was water flow problems with the 8mm micro bore radiator feed pipes but may be wrong. had a look at d40 and d41 at various boiler temperatue setting as i have found the higher the boiler temperatue setting the longer it will run and also the burner will reduce as temperatue rises as it does not at temperatures below 65oc just trips when two degree over sp. The following is the readings I got just before it tripped:-
60oc setting d40 61 d41 52
65oc 65 54
70oc 70 57
75oc 75 61
80oc 80 69

hope this all helps,
Switchmode.

 

[switchmode]

seems to have all squashed up, should read:-
60oc d40 61 d41 52
65oc d40 65 d41 54
70oc d40 70 d41 57
75oc d40 75 d41 61
80oc d40 80 d41 69

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[switchmode]

Any of you guys got any ideas

 

[DIYBaz]

Hey Switchmode,

Did you ever get to the bottom of this? I've got the same issue on the 24kw version of this boiler. Mine seems ok as lonng as I've got the CH set above 70, but below that I seem to have the same problem as you.

Watching it fire up I can clearly see it's going to overshoot & needs to turn the burner down, but it doesn't do it. Assuming there is some kind of setting that says it has to run full belt for the first 60 second or so, before it starts modulating.

If you've managed to find a solution please share.

Thanks!

 

[mickyg]

access D codes, adjust parameter to match the load. For a rough first try, allow 1.5 per radiator.

 

[bw65587]

I had the same issue with our Glow-worm Ultracom 38hxi.

When it was installed, it was left at the full output of 38kW which was massively too high for the existing rads we had (know that now!).

The effect was that it sounded like a 747 took off from our kitchen every so many minutes with the boiler temp racing to 82C before cutting out. Result was that the rads failed to heat. Basically there was nowhere for the power to go!

Anyway, I calculated our existing rads and DHW to be around 14,000 watts so down rated the output (d0) to 14kW. The difference it has made is incredible. Hardly any noise from the boiler and rads heat great. Basically boiler output now matches output of rads and DHW.

Boiler temp set to 80C and we get flow (d40) at 80C and return (d41) at 67C.

 

[mickyg]

Boiler temp set to 80C and we get flow (d40) at 80C and return (d41) at 67C.

try setting the temperature lower. With 67 on the return your boiler won't be condensing and therefore won't be as efficient as it could be. Try and get the return temp down to 50c providing the rooms still heat up sufficiently of course.

 

[bw65587]

Thanks mickyg.

Sorry. Haven't dropped it back down from that first week in the year when I increased it to 80C. Brrrrrr! It can go back down now like you suggest.

 

[hammerswinger]

Hi,
Can I ask what you think of the Ultracom boiler range as I'm looking for a replacement for my old combi boiler.
I've got a few on my short list and this is one of them.


Cheers.

 

[bw65587]

Hi hammerswinger.

I'll leave it to the experts here to answer your question on a technical/product level as there's been times I would have ripped ours off the wall and thrown it away! However, I hasten to add that my opinion is tainted by the experience we had with the installer and Glow-worm as a company. I am beginning to like the boiler now that it's been correctly installed and set up.

Ours isn't a combi so can't offer an opinion on that.

What I would recommend to you is NOT to use Glow-worm's 'Find an Installer' facility on their website (or use with extreme caution!). We used the installer at the top of the list for our postcode and got a cowboy! Glow-worm didn't want to know and it took them a month and me chasing their MD to respond to my complaint letter - so much for their customer service charter! In the end, I got BG to correctly reinstall it at my additional expense after all Glow-worm would offer was to check the installation once it had been correctly installed! No kidding - on their recommendation, it should have been installed correctly in the first place!

So, I'm not bitter!

Happy shopping!

 

[hammerswinger]

Hi,
Thanks for your advice, I'll be using the services of a good friend of mine for the fitting so that shouldn't be a problem, he recomended a Vaillant but I'm just looking around to see what else is out there & how the prices compare.


Cheers.

 

[mickyg]

Hi,
Can I ask what you think of the Ultracom boiler range as I'm looking for a replacement for my old combi boiler.

One of the most reliable boilers around. Alot of people are put off installing them as Glowworm have built a few bogies in the recent past, but this one is solid. Most of the parts used are tried and tested over a number of years. I worked for Glowworm for 2 years and hardly ever saw one.