Heatline C28 Hot/cold water problems!!!

[gingapete]

This is a long one, so you better have a nice cold drink or a cuppa to hand!!

I've been having a problem with my C28 5 year old for a while now where CH fires up for 30seconds then goes off for 15 seconds then back on again for 30 seconds etc etc... HW runs hot/warm/cold cold cold cold and back again. This has now gradually gotten worse.

I was advised to change thermisters and see if this worked, so i did and still no joy!

While i was doing this i noticed that the DV motor was leaking so replaced that and still no joy. The pin does move so not sure if this is the next thing to look at the DV valve service kit?

Anyways, Agile quite rightly suggested (from another post) on checking the heat exchanger for blockages so i did the following:

Stripped the boiler down, cleaned the exchanger with Dam Buster gear and it was pretty clean nothing really came out. Flushed it for ten mins with hosepipe so nothing else in there.

Put it all the boiler back together and the DV started to leak again! So took it back off and checked it all again, it had water inside, so dried it with hairdryer and put silicone paste round it and clipped it back together and now it doesn't leak.

Put pressure back in system and all fine no leaks!

Booted the boiler up and only put on HW setting run the hot tap = Freezing cold! Ran for 10 mins still freezing! As i went to turn off the tap I brushed past my radiator in the kitchen and it was on, bloody roasting! So i turned off the tap and the radiator started to cool! At this point i was starting to cry with laughter and the missus thinks ive gone one flew over the cuckoo's or started on the sambuca early!!

So next thing i tried was switch on constant CH and the radiators fire up all nice n cosy! So i'm thinkin at least we got heating now!!

So i go back to the boiler and notice that the pressure is rising from 1.5, 1.7, 2.0, 2.5, 2.7 within ten minutes, so i switched it off before it went pop and took down my garage and then grabbed a cuppa and decided to start a new post, so here i am!

The missus ain't too happy at the moment as we ain't had heating or hot water for 2 days. At least we've got a elec shower, it's just not the best thing to be using to heat the house and do the dishes with though.

So something has got to start working pretty soon or crimbo is going to be spent round the neighbors!!

Agile, i started this post off here as the other one was getting a bit long and with the other being an old post i thought it would be best to start this one i wasn't fobbing you off m8 and cheers again for your reply! What do you think i could try next? And anyone else wants to throw some ideas at me i'm all ears even if there cold one's!!

Right time for a sambuca me tinks!

Pete

 

[twgas]

pressure problem is most likely the expansion vessel needs pumping up.
Running hot tap and getting hot rads is most likely the diverter valve not moving to HW position, if the motor pin moves when you run a tap its likely to need a new body or you reassembled it wrongly!

 

[gingapete]

Hi Mick,

Nice one i will check the expansion vessel and deffo think your right on the diverter valve, so i will re check that again.

Cheers
Pete

 

[gingapete]

DVM: I checked the DVM again, the pin shows right up to the front and does not move when turning on the hot water. But when i put the DVM back in to its housing on the DV and put the clip back in to retain it, water pours out from the joint. So the pin on the inside of the DV is hitting the shuttle type pin on the DVM and releasing the water. Now im not sure, but im thinking that that shouldn't be happening and the DVM may have become wet and stopped working? It doesn't seem damp, my nephew is a spark so is there a normal connection test that will show this up as still working? What amps should it be?

I can take the DVM apart and remove and change the wheel inside so the shuttle pin moves back to stop this happening, but im not sure if it is supposed to be flush or back a bit? I have tried it in both flush and backwards positions and it still sends hot water to the CH not the HW so the diverter is still not working. I will see if i can post a pic of it opened up as not sure if the switches have moved either...

When the boiler goes on and hot water is swicthed on should the DVM make any noise or hum or anything?

Expansion Vessel: The boiler is tight against a garage wall so it's difficult to get to where i think the expansion vessel is, but i am still trying to get to it!!!

 

[gingapete]

DVM and DV in case this helps?

Im not sure if the DVM wheel and pin is set in the correct position or if the switches are OK either. I have not touched the switches and only moved the wheel to move the shuttle type pin backwards.
The DV has been cleaned out this was taken beforehand. The staining on the base was from the old DVM which was leaking so got replaced by new DVM

The DVM pics are the new DVM showing pin and inside wheel position

DV

• gingapete
• 20 Nov 2011
• 1

I took this pic before i cleaned and dried the inside of the DV

New DVM

• gingapete
• 20 Nov 2011
• 1

I had to change the front as it seemed to close better on the DV, that's why the discolouring

Inside new DVM

• gingapete
• 20 Nov 2011
• 1

I have moved the wheel inside to stop the water flow coming out when trying to re-assemble the...

 

[gingapete]

Fond the expansion vessel at the back of the boiler and took the screw cap off and just pressed the valve a little bit to see if anything came out an there was nothing at all. So the vessel needs to be pumped back up but ive got nothing that i can put on it! So a bit buggered there!

Just wondering why has it all come at once? Is that the norm on boilers?

So still no HW & CH

 

[Slugbabydotcom]

Diverter valve is leaking and killing the motor. Put in a new valve (or valve insert kit if available) and then a new motor if necessary

 

[Slugbabydotcom]

If the PV has gone you can just add another to the system so long as you have the space. You can get a 8 or 12litre vessel, bracket and the pipe and fittings for less than about £45 from screwfix, use 15mm copper and just tee it into the system pipework. Its all about giving the water somewhere to expand to as it heats up.

 

[gingapete]

Update: I set the DVM so the pin was open and then plugged the cable back in to it and then put the elec back on the boiler and the motor does work because the pin moves back in to the flush position as shown in the second pic. But when i put the DVM in to the DV put the clip back in and re-pressure the system water is just pouring out of it now... don't remember there being any o ring in there so not sure if there should be one?

Right, that's it for me for tonight as got no way of getting the air back in to the expansion vessel, not sure why the water is leaking from the DVM/DV connection or why the DVM does not switch the CH over to HW when requested? Thank god for £9 Argos electric heater!!

Pete

 

[Agile]

I dont really understand what you are saying.

You should be able to repressurise the EXV if the rubber is not leaking.

The black gland needs replacing if its leaking.

Tony

 

[gingapete]

Tony: Sorry m8 im putting too much info in and confusing people i think.

EXV: I couldn't re-pressurize the EXV as didn't have anything to hand to do it with last night, but i will have tonight as one of the lads in work has a pump and a digi pressure gauge! I read that i need to drop everything out of the system so that i get a proper reading on the EXV, then once that is sorted i can re-pressurize the main system again?

EXV Rubber: The rubber should be fine as no water seems to be in the EXV.

Black Gland: I have ordered a HEATLINE DIVERTER VALVE REPAIR KIT PART NO. 3003202082 that should be with me by wed as i can get one quicker around here.

So the boiler will have had the new DVM and DV repair kit sorted.

So what looks like has happened over time is the gland has been leaking in the DV and gradually been wearing the o ring within the DVM causing it to blow the motor!

My next question is, with these two hopefully sorted by the weekend the DHW and CH "should" kick in ok?

Pete

 

[gingapete]

DV kit arrived and gland and pin replaced, all gunged up!! Dropped all pressure in system and re did the EXV, hot water and heating now on! The pressure is not rising, as think the EXV is pumped but now the temp goes up to 80 and then the boiler switches itself off.

I think i missed something!

Pete

 

[gingapete]

Got in touch with a mate who's a fitter and he worked out that the DVM wasn't working correctly so took it to bits and noticed that one of the switches wasn't correctly sitting (the blue one in the pic), reset it and silicon greased the bits and clicked it all down and checked and now when the HW is switched on the pin moves back it to position and hey presto HW!

We were still getting the boiler switching off and the blink on 80 flashing. Re seated the limit thermostat and bing back on again.

So ordered new limit thermostat and will be fitting that when it arrives!

So big thanks to Tony, Twgas and Slugs for persevering with me!

House is nice n hot and the hot water is working like its out of a kettle!!

So nice hot bath n bed for me n the missus!!

Pete

 

[Agile]

The high limit stat is a safety device and has no involvement with normal operation of the boiler.

I dont understand all that you are saying but I wonder if the plate HE is still blocked.

Tony

 

[gingapete]

Well when the boiler switched off and was blinking on the 80 led i pulled off the limit stat and re-seated it and it came back on.

After setting the blue switch in the DVM correctly meant the DVM will now switch between CH and DHW and now both CH and DHW are working like new.

I will see about the HE again this week if i get any re-occurance..

Pete