Pump running constantly with all controls turned off

[stfe1203]

Does anybody know why my pump is running constantly even with all the controls turned off ie programmer and thermostats. The only way I can stop it is to turn central heating off at mains. Very annoying on a night time. Also the boiler is short cycling all the time until I turn everything back on. I have a y plan system which operates fine until it comes to turning it off.

 

[Dotty]

Sticky 2 port valve. change the head.

 

[drip-dry]

Would be looking at any form of frost protection on system maybe

 

[chris watkins]

Sticky 2 port valve. change the head.

"I have a y plan system which operates fine until it comes to turning it off."

Not sure but I think that a Y plan uses a 3 port valve, I await to be corrected.

May still be resolved by head replacement.

 

[Dotty]

"I have a y plan system which operates fine until it comes to turning it off."

Not sure but I think that a Y plan uses a 3 port valve, I await to be corrected.

May still be resolved by head replacement.

Yeah fair one Chris. Pig of a day today, just walked in and fuming about some eejit posting nonsense on my FB page.

 

[lame plumber]

"I have a y plan system which operates fine until it comes to turning it off."

Not sure but I think that a Y plan uses a 3 port valve, I await to be corrected.

May still be resolved by head replacement.

this site now has 2 smart asses 🙂, thought you'd disappeared Mr W, not seen you for a bit.

 

[chris watkins]

Sneak in for a swifty every now and again, you can't get rid of an bum that easily, lame

 

[Ray Stafford]

some eejit posting nonsense on my FB page.

Thats you John. The eejit.

 

[lame plumber]

He popped up, I never went looking, only just saw him though 🙂, handsome little blighter.

 

[DrainMedic]

If it's a controls issue, sticky micro switch in the 3PV etc, then the boiler would be kicking in along with the pump.
Without seeing it, my best guess would be that it's been wired wrong, but this may be a mile off if it's been working right and suddenly stopped switching off!
Given the time of year, it could well be a frost protection measure, with some systems just having the pump running to prevent the water in the pipework freezing. If it gets much colder, the boiler may well kick in to keep the water above 5 deg, or some other preset temp.

 

[stfe1203]

Thanks for the replies. The actuator on the 3 port valve was changed not so long ago, I have double checked that everything functions when switched on and off ie valve changes to correct direction when I turn off programmer for DHW or CH and when the thermostats are turned up and down on cylinder and in room. Could it be the pump over run thermostat that is stuck on as Im getting a permanent live to the pump when the boiler shuts down. Also there is no frost stat fitted so I ruled that out as well.

 

[stfe1203]

Powered system down last night with all programmers and thermostats turned down and off. This morning when I powered it back up again the pump and boiler started up together. The pump was running constantly and the boiler fired up and a few seconds later turned off and repeated this over and over until I turned the programmer on and called for the central heating and turned up the thermostat, the same happened with the hot water. The radiators and hot water are now heating up as they should but when all turned off the same happens again.

 

[DrainMedic]

Does the boiler have internal frost protection? I'd be checking for any stats inside (while boiler is short cycling) and then heating them up to see if it changes anything. If the stats are cold, that may explain why they're calling for heat but only for short periods, especially if the pump is constantly running and cooling them back down quickly.

 

[stfe1203]

By turning the boiler thermostat to off stopped the boiler stopping and starting but the pump is still running.

 

[gassafe]

What boiler is it? The pump may be fed from the boiler?

 

[bright spark]

If not overrun stat, could be pump powered through PCB. Might need replacing. Depending on boiler. Think ye might need to get someone in to have a look!

 

[gassafe]

Open the wiring centre & see where the pump live is fed from...

 

[bright spark]

All due to stfe 1203, but if it's getting to d stage of checking wiring centres or power from PCB/ inside boiler casing, I think it's time to get a gas registered engineer in, no point fiddling about to 'save' yourself money. Think of your and your family's safety.

 

[stfe1203]

I am going to get professional help but just wanted to gain some knowledge myself along the way. My Dad is a qualified electrician but doesnt fully understand central heating systems and retired a few years ago so is a little rusty. Thought it might be a simple quick fix solution but starting to think now that its not. Thanks for everyones advice and feed back tho. Much appreciated.

 

[DrainMedic]

Oh dear! I didn't realise STFE1203 wasn't a plumber! Sorry STFE! Here's me advising you get your boiler stripped down!
With the new information in mind, definitely get someone in to deal with you issue, and please make sure they're on the GSR, like Bright Spark says, no point fiddling and putting yourself in danger.