No hot water, central heating is working and its a back boiler? possible pump issue?

[david123]

Hi,

We have no hot water, checked tank and all is full. The central heating is fine. I am thinking the pump? just wondering if it is. where can I get one from and are they easy enough to fit? Please see fit other current one

 

[mountainman]

Hiya
If your heating is working then it's unlikely to be the pump.
More likely a motorised valve but you have given insufficient information to be more help to you.

 

[david123]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Thanks for that, please let me know what information you require. thanks

 

[AWheating]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

if thats your pump id be supprised you had much in the way of controls? post a picture of your air cupboard/cylinder set up. your hot water may be gravity?

also dont put your hands near that capacitor it looks like its seen better days. if you turn the power off best to it leave it alone for alittle time to allow it to decharge.

 

[david123]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Thanks for the reply. The company we used over ten years ago did cut corners. we always get the upstairs radiators on when the hot water is on.

Anyway, will post picture of the air cupboard later when im back. The pump was just to the left of the gas fire, should I post pics of the pipes there as well?

thanks

 

[AWheating]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

the more pictures the better 🙂

 

[mountainman]

Ha Ha, silly me; I didn't look at the pump piccy. Is that a Sunstrandt pump??

IMO this problem needs professional hands-on advice.

 

[aggis]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

If it's a fire back boiler, looking at the photo of the pump it tells me it's an old system, therefore your hot water cylinder is more than likley supplied by a gravity circuit & if you header tank is full, it's either someones turned the cold feed valve to the system, off, or more than likley a blockage. My guess it would be in the tee that connects the cold feed to the return on the cylinder.

If there is a second pump on the system [ it'll have 3 connections] a SMC controller pump that supplies the cylinder, it's probably that that's gone. Usually the 2 pumps are next to each other. This second Type of system is very rare & would need converting to a Y plan as the controller pump I now think is obsolete.

 

[jtsplumbing]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

My god aggis are you old enough to remember the SMC control pack ? :wheelchair: not seen one for years,

 

[mountainman]

I'm not sure the OP will understand this stuff (I stand to be corrected).
I still recommend the professional hands on approach.

 

[jtsplumbing]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Looks like a nice easey pump change !! has it got any valves ??

 

[stevetheplumber]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

theres no way that pump is ten years old 40 at least

 

[david123]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

If it's a fire back boiler, looking at the photo of the pump it tells me it's an old system, therefore your hot water cylinder is more than likley supplied by a gravity circuit & if you header tank is full, it's either someones turned the cold feed valve to the system, off, or more than likley a blockage. My guess it would be in the tee that connects the cold feed to the return on the cylinder.

If there is a second pump on the system [ it'll have 3 connections] a SMC controller pump that supplies the cylinder, it's probably that that's gone. Usually the 2 pumps are next to each other. This second Type of system is very rare & would need converting to a Y plan as the controller pump I now think is obsolete.

These are the pictures above and below the pump. I cannot see a second. if you could tell me in simple terms what to possible do to fix it. Also, with the pump being about 40 years old, is there any point in changing it, even if it turns out to be working fine?

thanks

 

[Bernie2]

Re: No hot water, central heating is working and its a back boiler? possible pump is

Yes does look a bit like an old SMC or Cadet Commander. As said though before you touch it, is it the central heating that is not working or the hot water? It was usual to have the hot water cylinder on a separate circuit (Called a Primary circuit) from that of the central heating coming from the boiler. In other words it has four pipes coming from the boiler, with depending on a few things the possibility of another two i.e cold feed and vent to boiler.

It was usual though to place the cold feed and vent on the Primaries teed in by the cylinder.

The pump was usually fitted on the central heating side to push the water around with force. The hot water side usually worked by gravity without a pump. But there are a lot of variations.

I would check the roof space first to make sure the small central heating tank was getting water and that the water in it was about 50mmover the pipe coming out the bottom of it. However once again you could have no tank and the system fed through a primatic cylinder. However checking the header tank is probably the first thing a Plumber would do, its very common for the ball valves on them to seize up. Then go around bleeding the air out of the system if you can. Then listen to make sure the tank is filling as another problem could be a blocked cold feed. I may also add that if the system is gravity fed and the back boiler is not getting water its a dangerous situation. Also feel the two Primary pipes to the cylinder to make sure they are heating up. I would Google a pipework layout for an indirect central heating and hot water system if I was you, it is far easier to understand it in pictures than writing about it. Try the UK copper board site or even Wickes which ever one you find easiest to understand. I think when you look at the layouts it becomes fairly obvious what I am on about.

 

[jtsplumbing]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Think that pump needs replaceing ! just because it makes a noise dosnt mean it's working properly, you will be amazed what differance a new pump will make.

 

[Nostrum]

Re: No hot water, central heating is working and its a back boiler? possible pump is

Yes does look a bit like an old SMC or Cadet Commander. As said though before you touch it, is it the central heating that is not working or the hot water? It was usual to have the hot water cylinder on a separate circuit (Called a Primary circuit) from that of the central heating coming from the boiler. In other words it has four pipes coming from the boiler, with depending on a few things the possibility of another two i.e cold feed and vent to boiler.

It was usual though to place the cold feed and vent on the Primaries teed in by the cylinder.

The pump was usually fitted on the central heating side to push the water around with force. The hot water side usually worked by gravity without a pump. But there are a lot of variations.

I would check the roof space first to make sure the small central heating tank was getting water and that the water in it was about 50mmover the pipe coming out the bottom of it. However once again you could have no tank and the system fed through a primatic cylinder. However checking the header tank is probably the first thing a Plumber would do, its very common for the ball valves on them to seize up. Then go around bleeding the air out of the system if you can. Then listen to make sure the tank is filling as another problem could be a blocked cold feed. I may also add that if the system is gravity fed and the back boiler is not getting water its a dangerous situation. Also feel the two Primary pipes to the cylinder to make sure they are heating up. I would Google a pipework layout for an indirect central heating and hot water system if I was you, it is far easier to understand it in pictures than writing about it. Try the UK copper board site or even Wickes which ever one you find easiest to understand. I think when you look at the layouts it becomes fairly obvious what I am on about.

My god, talk about a fast track plumbing course!

have you got a mechanical thermostat on the cylinder?

 

[mountainman]

My god, talk about a fast track plumbing course!

have you got a mechanical thermostat on the cylinder?

I think it's hidden behind the pump, you can just see the weep lines. but the programmer is clockwork for sure.

Hands up those who remember Relay Valves lol

 

[Nostrum]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Can't say I do, I may have come across them but never known what they were?

My moneys on the cylinder stat, looks like gravity h/w to me so unless the system has recently been drained and airlocked or something there is nothing else it can be.

 

[david123]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Well finally got one out and they said its a air lock. So turned the hot water up all the way and turned the pump up to max. Said leave it few hours and turn back. However, he has left the pump still on max andI cannot turn it down by using screw driver. Any ideas or will I have to call them out again

 

[stuartty1]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Hi . Just reading this article and I have the exact same problem. Back boiler with central heating working and no hot water. What was the outcome for your problem. Was it the pump right enough. Cheers

 

[kris]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Hi . Just reading this article and I have the exact same problem. Back boiler with central heating working and no hot water. What was the outcome for your problem. Was it the pump right enough. Cheers

If your heatings working then the pump is ok, it will either be a 2 port or a 3 port motorised valve that's the fault,

 

[kris]

Re: No hot water, central heating is working and its a back boiler? possible pump iss

Or cylinder stat soz