Probably a stupid question about pump running continuously

[leaks]

Hi

New to the forum and I have a question which is probably pretty basic but I can't find anywhere on net with an answer to it!

It is, are central heating pumps designed to stop when they can't pump water due to the circuit being closed due to water and heating stats closing the motorized valves?

The reason I ask, is that our system is fully pumped with two 2-port motorized valves and the pump runs continusouly (with boiler coming on periodically) event when stats turned down and controller off so I suspect that the motorized valve to the how water cylinder is faulty (since central heating does go off as expected). There is a gate valve at the bottom of the cylinder which I think is the output of the heat exchanger (the existing MV is just above that on a pipe around the middle of the cylinder) so I was wondering if a temporary solution to stop the hot water running all night could be to close this gate valve at night. When the heating valve shuts too, would that stop the pump from running or could it break the pump even?

Any advice most gratefully received !!

 

[Bartdude]

Yes when the cylinder and room thermostats are satisfied the motorised valves should shut and in turn stop the pump and boiler. Some boilers require the pump to run on for a while after the boiler shuts down,but only until the boiler cools down.It sounds like a problem with wiring somewhere. Is it a new system,and what boiler do you have?

A photo of the set up might help,but I wouldn't turn off a valve,better to turn off the power to the boiler.

 

[leaks]

Many thanks for your answer. When you say "..and in turn stop the pump..", is that a physical stopping of the pump because it can't pump because there is nowhere for the water to go or is it becomes there is an electrical shutdown of the pump at that stage?

 

[tipintim]

It is, are central heating pumps designed to stop when they can't pump water due to the circuit being closed due to water and heating stats closing the motorized valves?


Some boilers have a pump over run, after demend has been met via a stat it still pumps to disperse heat from boiler for a short period. (your
pump should not run indefinatly). Even when motorised valves fail there should be a by-pass fitted, which alows the pump to circulate back to the boiler.


1. What boiler have you got
2. Does your pump ever shut down
3. Do you run your heating all night

 

[Bartdude]

To answer your question leaks,No the motorised valve switches over and stops the power supply to the pump and boiler,at least it does when it's working correctly!

 

[washer]

One of your zone valves are faulty, and providing power to the boiler and pump when not required.

 

[leaks]

Boiler says "British Gas 3100 RD1". Looks like it has only 1 flow, 1 return and gas connection.
Pump is external in airing cupboard and also in airing cupboard are two motorized valves (bgm-vsp 2). There is also a separate box mounted on the wall which connects to the 2 valves - it says something like "Danger 230V " so I assume that' the power supply for the valves? Above that is the British Gas user controller.

We have both hot water and CH turned off at night but the pump runs all night and the boiler comes on and off sporadically.

 

[tipintim]

Danger 230 V === LOL

You need a new valve. Turn off when not need till you sort it.
You could end up turning by-pass off. That would creat more probs

 

[leaks]

😎

Makes sense so I'll defn not touch the gate valve. However, I've just seen the pump has an on/off switch on the side. Perhaps (until I sort out the MV) I could turn that off at night? Will the boiler just turn off itself then because any water it heated would just sit there?

The main problem with the pump and boiler running all night is that the boiler is in the garage which is difficult to access in the night/morning to turn off/on so if I could use the on/off switch on the pump until I fix the MVs that would be great. Any danger in doing that?

Sorry for all the questions and many thanks for your help so far.

 

[tipintim]

I would definatly pull the plug on this while you sleep and suffer the garage in the mornings and evenings.

You should get a gas safe reg guy to sort it for you. would not take him long to fix.

1. Has the pump got a plug on it, or are you looking at the speed setting ?

2. Where in the world are you leaks

 

[leaks]

Its got a switch on the side which appears to turn it off. Should be safe to do so?

Leaks? Ahh....the latest was the main internal stopcock causing an emergency call to the water company to shut off the water...

 

[Bartdude]

If it's an electrical on/off switch that should be ok. It's probably the isolation for the whole boiler system.

I think tipintim was asking where you lived!!

 

[tipintim]

Post a picture of what you got?

As said, you have got a problem with m/v and also it could be something else. I would isolate whole system from power

untill its fixed. When you say a switch, is it in the wall or on the pump itself??

 

[tipintim]

lol bart

thought i was loosing the plot then for a minuite.

 

[leaks]

oops must be me losing the plot after all these hassles - I thought you wre asking where my leaks were LOL. I'm in SE near wokingham.

Yes its on the pump itself and has three positions labelled "I II and III" so I guess it is speed after all. I guess no harm leaving it on I (rather then III which its currently on) ?
Its just all the pipes make a lot of noise a night (which is next problem for me) so as a temporary solution and to get some good sleep was hoping to turn down pump. (Actually, if I leave switch half way between two positions I notice the pump goes off completely but I guess that is really asking for trouble doing that).

Re gas engineer, there's no gas involved in this is there? I was hoping to try to avoid large fees but maybe as you say its unavoidable.

 

[tipintim]

Maybe a gse on this site that lives in wokingham can help. that was the idea leaks.

Leaving it on 1 might make it quiter at least. Using the speed control between settings will cause more probs.

Have to wear a coat to bed bud.

It sounds like you need the system looking at, so good luk with the gse

 

[TGor]

The pump is probably wired wrongly into the controller .. I have seen this done purposely on systems where banging and pipe noise is a problem when the pump kicks in .. i.e leaving the pump running avoids the noise.