worcester 28cdi

[bassmonster]

The problem is with my own boiler - RSF model.

The problem is intermittent when i run the DHW. Sometimes it can take anything up to over a minute to get any hot water running. When running water for a bath, the fire just goes off with the red flashing (the light with the flame picture). Pressing the reset button for a few seconds fires up the boiler again..... heating is absolutely fine.

what can be the problem?

 

[kris]

If heatings fine it could be diverter valve hot water side . It maybe the micro switch that's attached to the diverter. This is located behind the plate heat exchanger on the front of these I think. Youl manage to test this easily. The plastic box attached to the diverter - get someone to open hot tap and watch the pin pop out and hit the micro switch if it fails to stay in position you know it's the Diverter. You may need to spin the plastic box to allow you to see the pin.

 

[kris]

Mind you your saying it goes to lockout does it ?

 

[kris]

Measure the resistance accross your dhw thermistor . The heatings defo perfect ?

 

[bassmonster]

hey Kris,
thanks for the replies.

i'll double check the heating.

yes, boiler goes into lockout with red light flashing..

what should the resistance be on the DHW thermistor with it being cold?

 

[kris]

The full range of thermistors go fro 5 degrees @ 28000 ohms to 90 degrees @ 1200 ohms so when your checking it it should be around 12000 to 13000 ohms that's around 25 degrees .

 

[gassafe]

Maybe a blocked plate heat, does it ever go hot cold hot?

 

[bassmonster]

I checked the boiler as soon as I got in. Central heating is on and I can see that the light with the tap is flashing...I let it flash for about 5 minutes. No fire but it's making a noise as if the pump over run is on... then turned on the dhw for about 10 seconds then heating was running fine......

 

[bewsh]

If the H/W light is flashing fast, then it's a sensor fault. If you look at the MI's, it'll take you through the diagnostics.

 

[bassmonster]

Hey all, I've not had a chance to look at my boiler yet but I'm at home today. Now, when you turn on the roomstat nothing happens... Only hot water working now...... Please advise...

 

[bigads28]

If it's changed the fault then it could be the board. The fault finding guide in the MI's is decent on that boiler.

 

[bassmonster]

This is rather strange. I've got one of those electric rs1 roomstat. I took off the front cover and checked the live and neutral which was reading 230v. I figured it was the roomstat. So I put the cover cover on and powered up the boiler. Went out and bought a honey roomstat. Before swapping over, I thought I'd check the rs1, it clicked and fired up the heating..... Must have been a loose connection I'm guessing.

I want to change the roomstat over to the Honeywell. I wanna get it right. There are 4 wires on the rs1. There's live (brown) , neutral (blue) , black (which I'm assuming is common?) and earth. I'm I right in saying that the live goes on terminal 1 and neutral on 3? Earth will go on ground terminal. What about the black wire or have I got it all wrong?

 

[Aquazone]

Black wire is calling. What honeywell stat you got?

 

[bassmonster]

It's the T6360. Managed to sort it out. Just in case any other new Gsr engineers stumble across this. Live (brown) has gone into terminal 1. Black into terminal 3. Neutral into 2 and obviously earth into earth terminal.

 

[Deleted member 64964]

Will most probably be plate to plate blocked up.

It will reduce the heat of the dhw and go to lock out.

Drop it out and let it soak in hsd extra for 20 mins do it again if really bad.

Don't forget to get some new orings before you start saves and leaky leaky lol

I've done loads of these