Has anyone used a submersible pump in an attic cold water tank?

PopeBuckfastXVI

We currently have an external pump sitting in the attic beside the water tank, and it's extremely loud and comes on at random times (system pressure has been checked and there's no leaks so I'd say it's something to do with the non-return valve or pressure bladder in the pump). We'll probably have to get a new one and I want to take the opportunity to get one that is as quiet as possible as the current one is very loud above our bedroom.

I was talking to a plumber who told me that a submersible pump inside the tank would be pretty much silent and wouldn't suffer from the same backflow problems.

Has anyone got one, and if so could you tell me what the noise levels are like?

Thanks in advance!

corkgsxr

They are much wider. But long enough so I doubt a standard tank would do.

Or can they be sideways in the tank?

PopeBuckfastXVI

That's interesting, he seemed to think he would get one to fit without any trouble, at least he didn't mention size being a concern.

rightjob!

you can fit a submersible pump in no problem in your standard tank.they are abit quieter.
what was your last pump sitting on?was it just screwed down onto plywood?

PopeBuckfastXVI

It's sitting on a big piece of insulation, the problem isn't even the amount of noise it's making (which is quite a bit), but that it keeps coming on in the middle of the night etc. If it wakes Mrs. Buckfast up it's got to go!

rightjob!

check the likes of toilets passing water,check the non return on the pump,the pressure in the vessel aswell,
or if theres a valve on the outlet of the pump close it off and see does the pump still kick on and off.

PopeBuckfastXVI

Thanks for the tips - the toilets are all sound, I think they are on a separate system anyway because the pump never comes on when they are flushed.

The plumber reckoned it was the non-return valve and replaced it with a new one, seemed to be a little better after that, but not much. I suspect a leaky bladder or something to do with the pressure in the tank myself.

Unfortunately I'm not very handy, so I don't know how much I would glean from looking at it!

corkgsxr

Turn off the valves before the pump. Open a hot and cold fixture so theres no pressure and pump the little tank up to about 1.2 bar.

If it wont hold pressure you need to change the little pressure vessel

PopeBuckfastXVI

corkgsxr wrote: »

Turn off the valves before the pump. Open a hot and cold fixture so theres no pressure and pump the little tank up to about 1.2 bar.

If it wont hold pressure you need to change the little pressure vessel

I'm afraid I only understood about half of that!

The pressure vessel is internal in the pump and I didn't see any pressure gauge on it the last time I looked at it.

This is the pump (not sure if right model, but that's what it looks like), for what it's worth:

http://www.plumbersurplus.com/Prod/Grundfos-MQ3-45-A-B-A-BVBP-230V-1-HP-Pressure-Booster-Pump-96515515/11070/Cat/541

Thanks for your answer!

nmacc

Pull off the big black cap on the end of the pump & you'll find the bladder underneath. Switch off the pump, shut off the valve on the inlet side (that's the horizontal fitting at the opposite end to the bladder, then run a tap to relieve the pressure.

Get a tyre pressure gauge & check the pressure. It should be around 1 Bar. If not, top it up with a footpump or bicycle pump.

By the way, a submersible pump will be quieter, but not by any means silent. You will definitely still hear it.

Does the MQ have flexible connections? If not, get two 1" flexible hoses. They should make a noticeable difference.

corkgsxr

nmacc wrote: »

Pull off the big black cap on the end of the pump & you'll find the bladder underneath. Switch off the pump, shut off the valve on the inlet side (that's the horizontal fitting at the opposite end to the bladder, then run a tap to relieve the pressure.

Get a tyre pressure gauge & check the pressure. It should be around 1 Bar. If not, top it up with a footpump or bicycle pump.

By the way, a submersible pump will be quieter, but not by any means silent. You will definitely still hear it.

Does the MQ have flexible connections? If not, get two 1" flexible hoses. They should make a noticeable difference.

I dont think so on the mq. Its more mechanical noise than vibration. I dont think flexys would do anything

nmacc

corkgsxr wrote: »

I dont think so on the mq. Its more mechanical noise than vibration. I dont think flexys would do anything

Quite the contrary, I've achieved considerable noise reduction for clients, just by fitting flexy hoses.

Dtp79

nmacc wrote: »

Quite the contrary, I've achieved considerable noise reduction for clients, just by fitting flexy hoses.

Interesting. Is this with the MQ pump?

nmacc

Dtp79 wrote: »

Interesting. Is this with the MQ pump?

Yes, with the MQ. I always use flexys on them now following a job a while back where the MQ was in the boiler room under the guest bedroom & plumbed with 1" copper. Client told me that every time the pump operated, the guest would wake.

Fitted flexys and they could no longer hear the pump upstairs, or anywhere else in the house - that made me popular!