boiler and pump keep cutting out, before thermostat satisfied!

[Mr Flux]

wel guys looking for some help with a problem at a house i was called up2 this evening! its a fully pumped vented heating system running of a standard oil boiler 3 zone on programmer upstairs down and hot water! Customer said that problem only started on thursday, when they turn the heating on rads only get luke warm! arrived up this evening and turned zones 1 and 2 on upstairs and down, boiler fired and pump started running all rooms stats where up full and calling for heat and boiler stat was up full! Anyway rads started 2 get warm and then after about 10 mins the boiler and pump shut off, only way 2 get rads warm was 2 put zone 3 on with them which is for hot water! Also when zone 1 and 2 is put on the thermostat on the boiler doesnt seem to be controlling the boiler if i turn it up or down it dosnt knock the boiler on or off but if i turn on zone 3 with 1 and 2 the boiler knocks on and off if i turn the thermostat on it up or down! any throughts guys?? thinking it could be electrical!

 

[diamondgas]

Not oil mate but it doesn't initially sound like an appliance issue! Does the boiler get up to temp? Does the boiler have a pump overrun? The latter can make a difference! Next I'd want to know if this was something knew, had any alterations done lately........lol ....That sort of thing! If all negative then how old is the system! If old then you got to think this should have shown by now if electrical otherwise system flow issue? First thoughts Mr Flux 🙂

 

[SimonJohns]

Sounds like a possible 2 port valve fault

 

[Mr Flux]

Sounds like a possible 2 port valve fault

Was thinking the same myself, strange the way it comes comes on when the hot water is called for ! surely a spark could determaine this with a test back at the programmer, to see which device is signaling the boiler to shut off before the desired temp is reached???

 

[SimonJohns]

im sure you could too if your confident using a multimeter

very simple test

 

[Mr Flux]

Not oil mate but it doesn't initially sound like an appliance issue! Does the boiler get up to temp? Does the boiler have a pump overrun? The latter can make a difference! Next I'd want to know if this was something knew, had any alterations done lately........lol ....That sort of thing! If all negative then how old is the system! If old then you got to think this should have shown by now if electrical otherwise system flow issue? First thoughts Mr Flux 🙂

no boiler doesnt get up 2 temp, not sure if it has a over run or not will get more time tomorrow to take a better look at things! No alternations have been made what so ever to the system id say its around 10 year old!

 

[Mr Flux]

im sure you could too if your confident using a multimeter

very simple test

No hate mutli meters.lol

 

[diamondgas]

You could try putting all the valves on manual or checking that they are open when they're supose to be yeh?

 

[Mr Flux]

You could try putting all the valves on manual or checking that they are open when they're supose to be yeh?

aye i will have another look 2mara and and if they are all working fine shes calling in the spark! let yaz know the outcome anyway guys! thanks for the advice 🙂

 

[Mr Flux]

hay guys just 2 update yous, called back to the house 2day when heating was off and tured on the zones 1 & 2 rad started 2 warm but as before the boiler and pump soon cut out before the room stat was satisfied! anwway i had a look around and found the 2port for the downstairs rads manually opened the valve and the boiler fired up again, after about 10 mins the rads all where hot! so i know its not a circulation problem, but when i turned it back 2 automatic the boiler shut off again even tho i have zone 1 and 2 lit on the controller panel and the room stat was lit up calling for heat! Anyway i ended up taking of the heads of zone 1 ans 2 and leaving the valve open and just told the customer to use the zone 3 (hot water) to heat all 3 zones until they get a spark to test the room stat and motorised valve for faults! think at this stage it has to be electrical?????

 

[Leo21]

Have you checked it's not the syncron motor in the zone valves. If the valves dont open fully making which sends power back to the boiler. Try turning the boiler stat to zero and check theres demand to the boiler.

 

[Mr Flux]

As i said when zones 1 and 2 are open the boiler thermostat dosnt knock the boiler on and off when i turn it up or down, only when i put zone 3 on does the thermostat on the boiler start working and kicks the boiler on and off when turn up or down! dont see how it could be the syncron valve because surely the motorised valve would open at all? The rad get luke warm and then the boiler and pump cut off!

 

[Mr Flux]

Have you checked it's not the syncron motor in the zone valves. If the valves dont open fully making which sends power back to the boiler. Try turning the boiler stat to zero and check theres demand to the boiler.

how do u check it?

 

[Leo21]

When the zone valve opens it has to open fully to hit an end switch inside the valve. The valve can open but not hit the micro switch which sends power back to the boiler. If it's honeywell valves take the top off and iff you look inside you will see the micro switch. Make sure it's hitting it. If not carefully put a neon screwdriver or any protected screw driver and push down on the switch and see if it fires up with the hot water off.