Water pump leak

[Yoda]

howson OK, confirmed tank bubble still there. Purged hot water out via the bay shower/water hose connection. Turned on elec and gas to get it going. 14 minutes the seeping started and water alarm went off a minute later.

Nothing above the pump. Photos attached. Photo 5 is the start of the leak.

Second photo - the black pipe top right - is there supposed to be a clamp there or a fitting of some sort? Just does not look right.
Keith

[Jlawles2]

Yoda Keith that looks like the thread on water screen. Hence the no clamp.

OP, I am thinking you have a pressure issue as Rob states. Been there fought it. By chance when the leak starts and you "burp" the hot water, do you notice a change in the apparent velocity / pressure. Mine would be a quick burst of high pressure then drop. Once it dropped, leak stopped.

[Jlawles2]

Has anyone considered adding a https://www.homedepot.com/p/Watts-1-...530C/205149183 to the hot water line or low point drain. Adjust it to a nominal pressure above the pump and city water regulator of say +5 psi. This will eliminate excess pressure build as the HWH heats up.

[Cate&Rob]

Has anyone considered adding a https://www.homedepot.com/p/Watts-1-...530C/205149183 to the hot water line or low point drain. Adjust it to a nominal pressure above the pump and city water regulator of say +5 psi. This will eliminate excess pressure build as the HWH heats up.

Hi Joseph,

I do not recall anyone doing this . . . but, I think it is a good idea. When the standard pressure relief on the water heater starts to drip, the system pressure is at 140 psi . Another way to come at this is with an expansion/accumulator tank which can absorb the water volume change with only a small increase in pressure.

Rob

[Rabbit]

I’m suspecting the check valve in the cold feed to the water heater is leaking allowing hot water expansion to over pressure the pump. A big coincidence for it to happen when you changed pumps, but I’ve heard stranger things happening. Shut off cold feed to tank and see if leak stops.

[TedS]

The leak appears to be from the pressure switch enclosure. The gasket/diaphragm may have failed or is faulty. We don't know what pressure that part will tolerate before failing.

This pump appears to be the same as the Seaflo 33.

[BobinICT]

howson Cate&Rob TedS

OK, you asked for it, you got it. Toyota! Well, pressure reading anyway. Dated and time stamped. 1) Initial gauge install and after checking tank bubble and line purge to get to all water in the lines and before heater start on gas and elec. 2) at time of leak starting. 3) After gas turned off. 4)After hot line burp, or, pressure release.

[Cate&Rob]

The pressure rise points to there not being an air dome in the water heater to absorb the water volume increase with temperature rise. How are you "checking tank bubble" ? Just popping open the pressure relief valve on the water heater may be releasing the pressure but not re-establishing the air dome. After opening the pressure relief, briefly open the low point drain to lower the water level in the water heater and draw in air through the pressure relief valve.

It is also possible that the configuration of your water heater and plumbing is somehow siphoning away the air dome in the water heater. In this case, an accumulator tank might be the simplest solution to preventing the significant pressure rise that you have observed.

Note to others following this thread . . . the pictures are not in chronological order . . . go by the time stamps 1 . . . 4 . . . 3 . . . 2

Rob

[TedS]

I agree, the pressure sequence indicates no waterheater bubble. An accumulator will take care of heated water expansion and limit the pressure rise. The water expands about a cup of volume when the temperature goes from cold(60F) to hot(140F).

[BobinICT]

The pressure rise points to there not being an air dome in the water heater to absorb the water volume increase with temperature rise. How are you "checking tank bubble" ? Just popping open the pressure relief valve on the water heater may be releasing the pressure but not re-establishing the air dome. After opening the pressure relief, briefly open the low point drain to lower the water level in the water heater and draw in air through the pressure relief valve.

It is also possible that the configuration of your water heater and plumbing is somehow siphoning away the air dome in the water heater. In this case, an accumulator tank might be the simplest solution to preventing the significant pressure rise that you have observed.

Note to others following this thread . . . the pictures are not in chronological order . . . go by the time stamps 1 . . . 4 . . . 3 . . . 2

Rob

The way I have been doing the tank bubble is I open sink valves in the bath, closest to the water heater, then open the pressure relief valve and then allow it to snap shut when the water flow stops. This is the first I've heard of opening the hot low point valve. (Yes, I did install gate valves to the low point drains.) As for installing an accumulator, there is not a whole lot of room for one anywhere in this rig. I'll try the low point part and report back later today.

[Cate&Rob]

BobinICT

The low point drain that you want to open is the cold one. You want to drop the water level in the water heater, so need to do this from the fill (cold water). The hot water low point drain will not accomplish this because of the check valve on the water heater outlet.

Rob

[Cate&Rob]

I’m suspecting the check valve in the cold feed to the water heater is leaking allowing hot water expansion to over pressure the pump. A big coincidence for it to happen when you changed pumps, but I’ve heard stranger things happening. Shut off cold feed to tank and see if leak stops.

BTW . . . there is no check valve on the cold water feed to the water heater . . . only on the outlet, and it is there only to prevent backfilling of the water heater when in bypass mode.

Rob

[howson]

BobinICT -- what Rob is conveying is actually something I do before every tow to drain the hot water tank completely (to save the 50 lbs of water sitting right over the heaviest tire). If interested it's documented here: https://gdrvowners.com/forum/operati...lling-the-plug

Howard

[TedS]

howson, closing the water heater bypass isolates the heater from the cold water line, including the cold low point drain. The water in the water heated can't flow out the low point drain. The valve should be set to not bypass the water heater so the water heater backflows to the cold line and drain. Or did I misread your process?

[howson]

howson, closing the water heater bypass isolates the heater from the cold water line, including the cold low point drain. The water in the water heated can't flow out the low point drain. The valve should be set to not bypass the water heater so the water heater backflows to the cold line and drain. Or did I misread your process?

Not the way my 315 is plumbed, Ted. Trust me, the process works! Been doing it for years now.

One of the cold water low point drains on my 315 is directly connected to the cold water input line that goes to the water heater (do not pass go, do not collect $200). When that low point drain is opened and the T&P valve is opened, air flows in the tank through the T&P and water drains out of the tank. The diagram in that other thread show this.

Turning the red valve on my P1 Nautilus shuts off any external (either city or from the fresh tank) from flowing into the (now empty) tank.