water pump issue?

[finest1]

hi all,

the central heating water pump at my parents house seems faulty. it makes unusual noises like gurgling, groaning noises that we never heard before. further to this after just 2 mins in the pump gets very hot and the boiler switches off. the pump itself was originally installed in 1986!! as its the oldest component i am guessing it is that.

the system is a condensing boiler (Worcester bosch 18Ri) with an F&E tank in the loft. the pump itself is SMC comet 130-45 installed 1986 we have NO cylinder

i have done the following to diagnose the system:

Drained F&E tank and refill. all works ok, ball cock works fine. tank drains at a steady rate and also fills at a steady rate.

i have bled all the radiators in the house starting at the bottom. all fine

i have ran a magnet on the pipes in and out of the tank, and around the water pump, no pull on the magnet

i have attempted to diagnose the actual pump, but when i take off the cover, i cannot find any bleed screw

after the above, the pump makes a loud whirring noise when switched on, it runs hot, but does not groan and gurgle. the boiler switches off after 5 mins

i am wondering, or seeking advice what else i can do to get the pump working and ultimately the CH back up working. is it a faulty pump?

previous to this the CH has been running fine. we estimate we stopped using it in may, and last week we put it on to test if the heating was working fine

i will attach some photos.

please note i am not a plumber or CH engineer, i am a DIYer with a splattering of knowledge and experience

many thanks in advance

 

[ShaunCorbs]

Pumps gone / cap

You can try testing the cap and then if bad changing the capacitor first if you want

 

[finest1]

thanks for your quick reply shaun. how can i be sure its not an airlock issue? i don't mind changing the pump, its served us well! but it will be pointless having a new pump if i there are outstanding issues.

 

[ShaunCorbs]

Have you drained the system?

 

[finest1]

Have you drained the system?

hi shaun, yes, i drained the system to check for any cold feed blockages on the F&E tank. there was no issues. it drained and filled up at a steady rate

 

[ShaunCorbs]

Did you fully drain the system or until you heard the tank running ?

 

[finest1]

Hi Shaun, I was actually up in the loft. I watched the tank drain all the way , and watched fill back up, if that’s what you mean, thanks

 

[finest1]

hi all update:

i drained the tank in the loft and all the radiators today. i then went through the bleeding process once the water was reinstated. there was no issues with the tank re-filling and the ball valve closing the water. after the whole process. i attempted the central heating and same result. the boiler lasted 2 mins and shut off. the pump was not making excessive noise but it didn't "sound" right. whole process took me 2.5 hours.

any suggestions?

thanks

 

[ShaunCorbs]

Turn the hot water on only and the boiler temp to min and let it run

 

[finest1]

Turn the hot water on only and the boiler temp to min and let it run

hi Shaun just a reminder that this is a condensing boiler not a combi. the boiler is for the central heating only. however, do you still want me to try?

thanks

 

[ShaunCorbs]

Yes as the hot water circuit eg upto the cylinder is the shortest circuit normally any bleeder / venting points around the cylinder?

 

[finest1]

hi shaun, just to remind you i don't have a cylinder. you want me to still try?

 

[ShaunCorbs]

How do you have hot water then ?

 

[finest1]

we get domestic water via a " Main Multipoint BF ERP Gas(Natural)Water Heater" in the bathroom which supplies our hot water for bathroom and kitchen

 

[ShaunCorbs]

That’s fair enough so shut all the radiators but the closest one to the pump and then run the system

 

[finest1]

OK i'll give this a go tomorrow, and i will update you. thanks for your time😀

 

[finest1]

hi Shaun, i gave it a go. for a heartbeat i thought it was going to work! however it didn't. same as above, boiler shut off.

thanks

 

[ShaunCorbs]

Did you keep bleeding any air off the rad !

 

[finest1]

dear all, thanks for your advice. i'd like to give you an update:

i called in a CH engineer to help resolve the issue. to cut a long story very short, he did think there maybe 2 issues, airlock, or water pump. he decided to go down the water pump route and said lets see what happens. he changed the water pump and then bled the boiler. so i have no issues there. during the install he had to apply force to remove the pump, that's fine we knew that from the conversation above. so all was fine, everyone happy. however during the install he decided not to change the valves to the new ones. i asked why. he said 1) we would have to drain the system and could cause an airlock 2) the valves are fine, no need changing them if we don't have to. i was surprised by this, and told him so, but took his advice. all good. i went to check the install hours later, and saw the water pump and valves wet. it was almost like it was sweating, but we had to put a container under to catch the drip. i text him and sent a video. he said he will come next day and he did. however, this is the heart of the matter. he tried to tighten it and the weep was still there. he then says to me, "your valves are defective". i reminded him that he confirmed the valves were fine and they didn't need changing, so you cannot tell me that i have defective valves. they weren't defective for over 30 years. he then said there is nothing he can do, he will have to charge me to change them. his job was to change the water pump only, valves wasn't part of the job. i then replied and explained to him that when i booked a job with the office, i said my CH doesn't work, i think its the water pump. during the conversation i told them i have the pump and valves on site. I told him all this when he came to the house, and gave him the pump and valve to hand. he declared its a separate job, nothing he can do and left.

at this point, i think its worth me saying that when i booked the job, i asked the office if the engineer can call me before hand as i will be happy to drain the tank, if that helps save time. the office said that they will get him to ring. he didn't, i didn't hear anything, he phoned me to say he's outside my house. he was two hours early, which i wasn't complaining about.

i lodged an investigation with the firm which, as you can imagine, is slow. promises of "I'll call you back" but never do. the latest conversation is that they are willing to replace the valves but its chargeable.

so i am hoping to get some perspective on this. i feel that the company should replace the valves with no cost as the engineer had caused some damage to it, they don't think so. they're stance is that they were only there to change the water pump.

what do you think?

thanks

 

[ShaunCorbs]

The valves are fine did he clean the face up and put new rubber washers on

If he damaged the nuts you can replace these by just using the slots on the underside of them and removing them

Would call them back and say it’s leaking and you want there insurance number as it’s going to cause damage

 

[finest1]

The valves are fine did he clean the face up and put new rubber washers on

hi Shaun. yes he cleaned the threads and changed the rubber washer which came with the pump.

If he damaged the nuts you can replace these by just using the slots on the underside of them and removing them

can you direct me to where this is? i upload a photo

Would call them back and say it’s leaking and you want there insurance number as it’s going to cause damage

i have a video which i sent to him. can i upload it here?

thanks

 

[ShaunCorbs]

https://www.stevensonplumbing.co.uk/images/source/Plumbing/heating/pump_valve_nut.jpg

Do you see the open two slots you can remove by tilting the nut and sliding it through the face on these

Tbh shouldn’t be leaking providing both the pump faces and the body faces are clean

 

[John.g]

I've seen those slots Shaun on the very few that I've changed but a bit confused as to what exactly their purpose is?.

 

[ShaunCorbs]

I've seen those slots Shaun on the very few that I've changed but a bit confused as to what exactly their purpose is?.

So you can swap the nuts

 

[finest1]

here are the videos:

water pump valve leak 1

water pump valve leak 2